Move path constants to proper fs crates

[kirillt]

We have multiple "path constants" defined in the fs-storage crate:
https://github.com/ARK-Builders/ark-rust/blob/main/fs-storage/src/lib.rs

However, none of them belong to this crate:

• ARK_FOLDER = ".ark"

  • The most generic constant necessary for any fs crates, all apps which persist something on disk using fs crates will use this constant to locate the folder with internal app data. What about fs-core? Would we have other definitions in fs-core?

• TAG_STORAGE_FILE = "user/tags", SCORE_STORAGE_FILE = "user/scores" and PROPERTIES_STORAGE_FOLDER = "user/properties"

  • Denote specific storages for user-defined metadata (should not be lost if possible, and we cannot restore the data). These constants must be defined in fs-tags, fs-scores and fs-properties.

• STATS_FOLDER = "stats" and FAVORITES_FILE = "favorites"

  • Denote specific storages enhancing user experience (should not be lost if possible, but we can restore the data). These constants must be defined in fs-tags-stats and fs-favorites.

• METADATA_STORAGE_FOLDER = "cache/metadata", PREVIEWS_STORAGE_FOLDER = "cache/previews" and THUMBNAILS_STORAGE_FOLDER = "cache/thumbnails"

  • Denote storages for generated data, or caches. We always can rebuild these storages from scratch. We need crates fs-metadata, fs-previews or fs-thumbnails to expose these constants.

• INDEX_PATH = "index"

  • Denotes location for the index, similar to caches we can build it from scratch, it would only cost us some time. Must be defined in fs-index.

[kirillt]

TL;DR
Crates:

• fs-core?
• fs-index
• fs-favorites
• fs-metadata
• fs-previews or fs-thumbnails
• fs-tags, do we need separate fs-tags-stats?
• fs-scores
• fs-properties