feat: add endpoint for user created calibrations

[bencap]

This pull request adds a new API endpoint for users to list their own score calibrations and introduces comprehensive tests to ensure correct behavior and access control. The changes enhance user experience by allowing authenticated users to retrieve their calibrations and improve code coverage for this feature.

API Enhancements:

• Added a new GET /score-calibrations/me endpoint in score_calibrations.py that allows authenticated users to list all score calibrations they have created. This endpoint requires authentication and returns a list of calibrations associated with the current user.

Testing and Access Control:

• Added multiple tests in test_score_calibrations.py to verify:
  • Anonymous users cannot access the new endpoint (receive 401).
  • Authenticated users with no calibrations receive an empty list.
  • Users can see only their own calibrations, not those of other users.
  • Users see calibrations across multiple score sets if applicable.