add WCS to L2 and L3 models

[nden]

Resolves RCAL-749

Closes #1060

This PR addresses ...

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/Roman-Developers-Pull-Requests/559/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (3b242ed) 97.15% compared to head (92d1ed4) 97.19%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #302      +/-   ##
==========================================
+ Coverage   97.15%   97.19%   +0.03%     
==========================================
  Files          28       29       +1     
  Lines        2533     2564      +31     
==========================================
+ Hits         2461     2492      +31     
  Misses         72       72              

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[WilliamJamieson]

Looks like some of the comparison utilities need to be updated to accommodate the GWCS objects. It maybe as simple as updating

roman_datamodels/src/roman_datamodels/testing.py

Lines 57 to 58 in 3b242ed

	elif isinstance(value1, Model):
	assert_model_equal(value1, value2)

to isinstance(value1, (Model, gwcs.<type>))

[PaulHuwe]

LGTM