RCAL-905: Add ePSF, ABVegaOffset, and ApCorr Datamodels

[PaulHuwe]

Resolves RCAL-905

Closes #905

This PR adds datamodels and tests for ePSF, ABVegaOffset, and ApCorr reference files. Other tests were tweaked for this support. The PR template was also updated to match the one from the RAD library.

Tasks

• [x] update or add relevant tests
• [ ] update relevant docstrings and / or docs/ page
• [x] Does this PR change any API used downstream? (if not, label with no-changelog-entry-needed)
  • [x] write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types)
  • [x] start a romancal regression test with this branch installed ("git+https://github.com/<fork>/roman_datamodels@<branch>")

news fragment change types...

- ``changes/.feature.rst``: new feature - ``changes/.bugfix.rst``: fixes an issue - ``changes/.doc.rst``: documentation change - ``changes/.removal.rst``: deprecation or removal of public API - ``changes/.misc.rst``: infrastructure or miscellaneous change

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 97.87234% with 2 lines in your changes missing coverage. Please review.

Project coverage is 97.77%. Comparing base (087a60d) to head (55c9e1c). Report is 54 commits behind head on main.

Files with missing lines	Patch %	Lines
src/roman_datamodels/maker_utils/_ref_files.py	95.45%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #393 +/- ## ========================================== + Coverage 97.56% 97.77% +0.21% ========================================== Files 30 36 +6 Lines 2788 3460 +672 ========================================== + Hits 2720 3383 +663 - Misses 68 77 +9 ```

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[PaulHuwe]

RCAL regression tests: https://github.com/spacetelescope/RegressionTests/actions/runs/11097495928