Move "Tracing" feature into GitLab Core

This is an implementation issue to move Tracing within the Monitor stage into Core

This should have a sperate MR to update our documentation as well

MR story

1. Move Tracing project setting model to Core - !43869 (merged)
2. Move Tracing usage data ping to Core - !44006 (merged)
3. Move Tracing operations service to Core - !44303 (merged)
4. Move Tracing operations controller to Core - !44323 (merged)
5. Move Tracing controller to Core - !44604 (merged)
6. Move remaining parts of Tracing to Core - !44574 (merged)
7. Follow-up refactorings and tasks - #259282 (closed)
8. Documentation - !44768 (merged)