Add ?assignmentId query param for GET /user/cases endpoints

[benjaminkostiuk]

Currently have endpoints GET /case fetches test cases created by the user GET /user/cases fetches test cases created by the user

Need to add an extra query param ?assignmentId={XX} to allow filtering of results by assignment id. This will allow users to filter viewing of test cases by assignments in the UI.

• Make sure you've setup the test-runner repo + keycloak server.
• Find the UserApi and CaseApi interface and the getUserTestCases and getTestCases functions. Add a new query param (@RequestParam) for assignment id.
• Update the controllers that implement the interfaces and pass the new paramter to the case service.
• Update the CaseService getCases functions to accept the new assignmentId parameter and build the correct specification.

Verification:

• Make sure the new query parameter shows up when looking at the swagger UI.
• Test the endpoint to ensure it correctly filters cases by assignment id.
• Create new cases to ensure they can show up when accessing the /user/cases endpoint.

[benjaminkostiuk]

@youcefs21 This can be task 3.