Make internal_tracing.context_logger a public lib

[georgeee]

This resolves a circular package-to-package dependency between mina_base and internal_tracing.

Clarification

It's package-to-package circular dependency, not libray-to-library.
Dune handles it well.
But dependency diagram becomes way less readable, also it makes packages incompatible with findlib-based installation approach (because one can't install packages one by one, they depend on one other).

Explain how you tested your changes:

• Mina compiles

Checklist:

• Dependency versions are unchanged
  • Notify Velocity team if dependencies must change in CI
• Modified the current draft of release notes with details on what is completed or incomplete within this project
• Document code purpose, how to use it
  • Mention expected invariants, implicit constraints
• Tests were added for the new behavior
  • Document test purpose, significance of failures
  • Test names should reflect their purpose
• All tests pass (CI will check this if you didn't)
• Serialized types are in stable-versioned modules
• Does this close issues? None

[rbonichon]

I think this change is okay. Approving