Remove Tokio requirement and move into a user supplied spawner

[stevefan1999-personal]

This PR is part of #80 to remove Tokio from the library crate itself. The test and everything else (including the API usage) should still work the same.

However, this is still a major interface change (added a new trait bound) so a semver change is also required.

Together with #81, this should make SurrealKV truly runtime-free, and should be able to seamlessly integrate with other async runtime (smol, async-std) as well.

[stevefan1999-personal]

Tested on my WSL2 environment, all system go!

running 143 tests
test storage::cache::s3fifo::tests::test_push_and_read ... ok
test storage::cache::s3fifo::tests::test_push_removes_oldest ... ok
test storage::cache::s3fifo::tests::test_no_memory_leaks ... ok
test storage::kv::compaction::tests::test_recovery_state_sequentially ... ok
test storage::kv::entry::tests::encode_decode ... ok
test storage::kv::compaction::tests::insert_close_reopen_single_bulk_transaction ... ok
test storage::kv::entry::tests::txn_with_value_read_from_memory ... ok
test storage::kv::entry::tests::txn_with_value_read_from_clog ... ok
test storage::kv::compaction::tests::compact_skips_all_versions_if_last_is_deleted ... ok
test storage::kv::meta::tests::as_deleted ... ok
test storage::kv::meta::tests::bytes ... ok
test storage::kv::meta::tests::from_bytes ... ok
test storage::kv::meta::tests::new_metadata ... ok
test storage::kv::option::tests::default_options ... ok
test storage::kv::manifest::tests::test_manifest_append_and_load ... ok
test storage::kv::manifest::tests::test_add_and_read_multiple_manifests ... ok
test storage::kv::oracle::tests::waiters_new ... ok
test storage::kv::compaction::tests::compaction_with_all_keys_deleted ... ok
test storage::kv::compaction::tests::multiple_versions_stored_post_compaction ... ok
test storage::kv::oracle::tests::waiters_async ... ok
test storage::kv::compaction::tests::basic_compaction ... ok
test storage::kv::compaction::tests::compaction_with_sequential_writes_and_deletes ... ok
test storage::kv::compaction::tests::compaction_with_mixed_operations ... ok
test storage::kv::compaction::tests::compaction_with_overlapping_keys ... ok
test storage::kv::compaction::tests::compaction_persistence_across_restarts ... ok
test storage::kv::compaction::tests::compaction_with_random_keys_and_deletes ... ok
test storage::kv::compaction::tests::compaction_and_post_compaction_writes ... ok
test storage::kv::repair::tests::test_restore_files_multiple_clog_and_repair_files ... ok
test storage::kv::repair::tests::test_restore_files_multiple_clog_files ... ok
test storage::kv::repair::tests::test_restore_files_multiple_repair_files ... ok
test storage::kv::compaction::tests::compaction_with_random_reads_and_writes ... ok
test storage::kv::repair::tests::test_restore_files_multiple_repair_files_with_data ... ok
test storage::kv::repair::tests::test_restore_files_single_clog_and_repair_files ... ok
test storage::kv::reader::tests::reader ... ok
test storage::kv::compaction::tests::compact_handles_various_key_versions_correctly ... ok
test storage::kv::compaction::tests::multiple_versions_and_single_version_keys_post_compaction ... ok
test storage::kv::compaction::tests::compact_handles_various_key_versions_correctly_with_clear ... ok
test storage::kv::snapshot::tests::test_versioned_apis_with_snapshot ... ok
test storage::kv::snapshot::tests::test_versioned_apis ... ok
test storage::kv::store::tests::changing_max_segment_size ... ok
test storage::kv::store::tests::clone_store ... ok
test storage::kv::store::tests::concurrent_test ... ok
test storage::kv::store::tests::decreasing_max_key_value_size ... ok
test storage::kv::repair::tests::read_across_segments_from_disk ... ok
test storage::kv::store::tests::eventual_durability ... ok
test storage::kv::repair::tests::repair_with_one_record_per_segment ... ok
test storage::kv::store::tests::eventual_durability_records_persist_after_drop ... ok
test storage::kv::store::tests::immediate_durability ... ok
test storage::kv::store::tests::eventual_durability_records_persist_without_wait ... ok
test storage::kv::store::tests::increasing_max_key_value_size ... ok
test storage::kv::store::tests::basic_compaction1 ... ok
test storage::kv::repair::tests::repair_with_corruption_in_first_segment ... ok
test storage::kv::repair::tests::repair_with_corruption_in_middle_segment ... ok
test storage::kv::repair::tests::repair_multiple_segment_with_multiple_records_with_corruption_in_first_segment ... ok
test storage::kv::repair::tests::repair_single_segment_with_multiple_records ... ok
test storage::kv::repair::tests::repair_multiple_segment_with_multiple_records_with_corruption_in_middle_segment ... ok
test storage::kv::repair::tests::repair_with_two_records_per_segment ... ok
test storage::kv::repair::tests::repair_multiple_segment_with_multiple_records_with_corruption_in_last_segment ... ok
test storage::kv::store::tests::store_closed_twice_without_error ... ok
test storage::kv::transaction::tests::basic_scan_single_key ... ok
test storage::kv::store::tests::stop_task_runner ... ok
test storage::kv::store::tests::records_not_lost_when_store_is_closed ... ok
test storage::kv::store::tests::store_open_and_update_options ... ok
test storage::kv::transaction::tests::basic_scan_multiple_keys ... ok
test storage::kv::transaction::tests::empty_scan_should_not_return_an_error ... ok
test storage::kv::transaction::tests::basic_transaction ... ok
test storage::kv::transaction::tests::insert_large_txn_and_get ... ignored
test storage::kv::transaction::tests::g1a ... ok
test storage::kv::transaction::tests::g2_predicate ... ok
test storage::kv::transaction::tests::g0 ... ok
test storage::kv::transaction::tests::is_send_sync ... ok
test storage::kv::store::tests::insert_close_reopen ... ok
test storage::kv::store::tests::strong_durability_records_persist ... ok
test storage::kv::transaction::tests::g1b ... ok
test storage::kv::transaction::tests::g_single ... ok
test storage::kv::transaction::tests::multiple_savepoints_without_ssi ... ok
test storage::kv::transaction::tests::g_single_write_1 ... ok
test storage::kv::transaction::tests::g1c ... ok
test storage::kv::transaction::tests::multiple_savepoints_with_ssi ... ok
test storage::kv::transaction::tests::g2_item ... ok
test storage::kv::transaction::tests::mvcc_serialized_snapshot_isolation ... ok
test storage::kv::transaction::tests::g_single_write_2 ... ok
test storage::kv::transaction::tests::mvcc_serialized_snapshot_isolation_scan ... ok
test storage::kv::transaction::tests::ordered_writes ... ok
test storage::kv::transaction::tests::mvcc_snapshot_isolation ... ok
test storage::kv::transaction::tests::mvcc_snapshot_isolation_scan ... ok
test storage::kv::transaction::tests::savepoint_rollback_on_updated_key ... ok
test storage::kv::transaction::tests::ryow ... ok
test storage::kv::transaction::tests::savepoint_rollback_on_updated_key_with_scan ... ok
test storage::kv::transaction::tests::savepont_with_concurrent_read_txn_with_ssi ... ok
test storage::kv::transaction::tests::savepont_with_concurrent_scan_txn ... ok
test storage::kv::transaction::tests::savepont_with_concurrent_scan_txn_with_new_write ... ok
test storage::kv::transaction::tests::p4 ... ok
test storage::kv::transaction::tests::savepont_with_concurrent_read_txn_without_ssi ... ok
test storage::kv::transaction::tests::scan_multiple_keys_within_single_transaction ... ok
test storage::kv::transaction::tests::pmp_write ... ok
test storage::kv::transaction::tests::pmp ... ok
test storage::log::aol::tests::append ... ok
test storage::kv::transaction::tests::sdb_delete_record_id_bug ... ok
test storage::kv::transaction::tests::test_insert_clear_read_key ... ok
test storage::kv::transaction::tests::transaction_delete_and_scan_test ... ok
test storage::log::aol::tests::append_and_read_two_blocks ... ok
test storage::kv::transaction::tests::transaction_delete_scan ... ok
test storage::log::aol::tests::append_large_record ... ok
test storage::log::aol::tests::append_read_append_read ... ok
test storage::log::aol::tests::fsync_failure ... ok
test storage::log::aol::tests::append_after_reopening_log ... ok
test storage::log::tests::bytes_roundtrip ... ok
test storage::log::aol::tests::read_beyond_current_offset_should_fail ... ok
test storage::log::tests::metadata_extension ... ok
test storage::log::tests::new_empty ... ok
test storage::log::tests::parse_segment_name_invalid_format ... ok
test storage::log::tests::parse_segment_name_with_extension ... ok
test storage::log::tests::parse_segment_name_without_extension ... ok
test storage::log::tests::put_and_get_uint ... ok
test storage::kv::transaction::tests::transaction_delete_from_index ... ok
test storage::log::tests::read_reader_field ... ok
test storage::log::tests::bad_file_header ... ok
test storage::log::tests::check_and_validate_file_header ... ok
test storage::log::aol::tests::random_access_read_performance ... ok
test storage::log::tests::segment_name_with_extension ... ok
test storage::log::tests::segment_name_without_extension ... ok
test storage::log::tests::aol_reopen_empty_file ... ok
test storage::log::aol::tests::sequential_read_performance ... ok
test storage::log::tests::segments_empty_directory ... ok
test storage::log::tests::segments_non_empty_directory ... ok
test storage::log::tests::test_list_segment_ids ... ok
test storage::log::tests::write_reader_field ... ok
test storage::log::tests::segment_corrupted_metadata ... ok
test storage::log::aol::tests::append_records_across_two_files_and_read ... ok
test storage::log::tests::segment_closed_operations ... ok
test storage::log::aol::tests::append_and_reload_to_check_active_segment_id ... ok
test storage::log::tests::aol_append ... ok
test storage::log::tests::segment_reopen_file ... ok
test storage::log::aol::tests::append_across_two_files_and_read ... ok
test storage::log::aol::tests::test_rotate_functionality ... ok
test storage::log::tests::segment_append_read_append ... ok
test storage::log::tests::sync_on_synced_segment ... ok
test storage::log::tests::segment_reopen ... ok
test storage::kv::reader::tests::append_and_read ... ok
test storage::kv::store::tests::store_without_persistance ... ok
test storage::kv::store::tests::bulk_insert_and_reload ... ok
test storage::kv::store::tests::insert_then_read_then_delete_then_read ... ok

test result: ok. 142 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out; finished in 2.54s

   Doc-tests surrealkv

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

[arriqaaq]

Thanks @stevefan1999-personal

As mentioned here, will keep this for a future milestone as it will introduce many breaking changes at the moment.