Segregate integration tests into different processes.

[LuisPH3]

This PR segregates the different integration tests into their own package names. Therefore, they will be compiled into separate binaries which go test will execute in parallel.
This is done to speedup execution of unit tests, which during race detection can easily exceed timeout settings.

In addition:

• Count and test-net-test reuse running integration networks to avoid overhead
• Timeout time for the integration network startup has been increased to 5 minutes. Because race-enabled tests would time-out during initialization of the network, and produce false positives.

This pr is part of https://github.com/Fantom-foundation/sonic-admin/issues/50
This pr helps towards https://github.com/Fantom-foundation/sonic-admin/issues/47.

[HerbertJordan]

Looks good to me. Thanks for improving the life of us developers!

You might get into memory usage issues by running all tests in parallel. If you do, you can use the -p option for limiting the number of parallel processes go test is using to run tests.

[LuisPH3]

This PR has been moved back to draft because of a recurring failure in CI:

When running, go test ./tests/... everything seems to be alright. But when running go test ./... there are spurious test failures and/or termination signal received. This makes me think that there is yet some shared resource that does not get randomized correctly.

Because the race detector did not find any new race, when running it locally. I will park this work for the time being and focus on other tasks.
I will come back to this issue once the other issues are dispatched.