devcontainer & unit test refactoring

[kwitsch]

Devcontainer changes:

• removed slow extensions
• corrected autolinting
• added test extensions
• added lcov converter
• added volume for go package caching
• added task & launch configurations

Unit test changes:

• surrounded improper sections with BeforeEach
• fixed local variables by declaring them in a parent section
• use dedicated ports for each runner if tests are executed parallel

Workflow changes:

• disabled coverage upload on forks

Makefile changes:

• runs test and race with -p if GINKGO_PROCS isn't specified

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

see 2 files with indirect coverage changes

📢 Thoughts on this report? Let us know!

[kwitsch]

Thought of a better way to achieve automatic background testing.
Will push it after testing.

[kwitsch]

@0xERR0R & @ThinkChaos I started refactoring the unit tests in this PR to enable parallel execution. Since this is still flaky I disabled it in GitHub workflow execution. The GitHub runners provide 2 cores therefore enabling -p speeds test and race by only <1 minute during workflow execution.
Running make test locally with 8< cores the performance increase is significant.

I fixed the most problematic parts but there are still way too many local variables which are against the ginkgo principal (variables shouldn't be declared inside the deepest level). Also initialization should be done outside the test itself in BeforeEach, BeforeAll, etc.

I enabled parallel execution in make test and make race therefore these are flaky locally which helps identify the problematic tests so they can be fixed gradually.

[ThinkChaos]

Looks good to me. The port thing doesn't necessarily need to be changed now, do as you wish :)