RAD-155: Add 'basic' schema to 'wfi_mosaic'

[nden]

Resolves RCAL-nnnn

Closes #

The changes in this PR correspond to RAD-155 changes in spacetelescope/rad#390. pyproject should be updated before merging

Checklist

• [ ] Added entry in CHANGES.rst under the corresponding subsection
• [ ] updated relevant tests
• [ ] updated relevant documentation
• [ ] Passed romancal regression testing on Jenkins / PLWishMaster. Link: https://plwishmaster.stsci.edu:8081/job/RT/job/romancal/XXX/

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 97.51%. Comparing base (087a60d) to head (a42188a). Report is 6 commits behind head on main.

:exclamation: Current head a42188a differs from pull request most recent head 355494e. Consider uploading reports for the commit 355494e to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #328 +/- ## ========================================== - Coverage 97.56% 97.51% -0.06% ========================================== Files 30 32 +2 Lines 2788 2972 +184 ========================================== + Hits 2720 2898 +178 - Misses 68 74 +6 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[nden]

@PaulHuwe Thanks for the review. This is ready now for final review.