Added unit test data for RefNLPEP2D forward operator and associated variable transforms

[steve-marshall-piq]

Description

This is the unit test data related to the RefNLPEP2D forward operator: anew 2D GNSSRO forward operator based on refractivity that simulates a path-integrated variable called nonLocalPseudoExcessPhase.

Issue(s) addressed

There is no issue number associated with this PR.

Dependencies

The is related to a PR in ufo that provides the code for RefNLPEP2D. It is also related to a documentation PR in jedi-docs.

List the other PRs that this PR is dependent on:

• [https://github.com/Addition of the RefNLPEP2D GNSSRO forward operator JCSDA/ufo#77] ...
• [https://github.com/Documentation for RefNLPEP2D forward operator and variable transforms JCSDA/jedi-docs#47] ..

Impact

No downstream impact is expected. This PR only adds new unit test data files. It makes no changes to existing files.

Manual Testing Instructions (optional)

These are the new ufo unit tests that are related to these data files:

• ufo_test_tier1_test_ufo_opr_gnssrorefnlpep2d
• ufo_test_tier1_test_ufo_linopr_gnssrorefnlpep2d
• ufo_test_tier1_test_ufo_variabletransforms_nonlocalpseudoexcessphase
• ufo_test_tier1_test_ufo_variabletransforms_gnssrorefractivitygradient

The ufo-data units tests are:

• ufo_data_validate_gnssro_obs_2025070400_refnlpep2d.nc4
• ufo_data_validate_nonlocalpseudoexcessphase_transforms.nc4
• ufo_data_validate_gnssrorefractivitygradient_transforms.nc4

Checklist

• [ X] I have performed a self-review of my own code
• [X ] I have made corresponding changes to the documentation
• [X ] I have run the unit tests before creating the PR