Add Test for CONUS Standard AnA and Refactor Test Configuration

[mxkpp]

This refactors the test configurations to support extensibility, and extends the tests by adding one for CONUS Standard Analysis & Assimilation (AnA).

Additions

• AnA test: ./tests/ana/test_ana.py
• Run from Dev Container via:
  • ( cd src/ngen-forcing && pytest tests/ana )
  • ( cd src/ngen-forcing && mpirun -n 2 pytest tests/ana )

Removals

Changes

• Refactored test configuration structure

Testing

1. Ran existing tests. InputForcing -n 2 is not currently passing but InputForcings -n 1 is (unrelated to this PR).
2. Created new test data (expected results) for the new AnA case.

Screenshots

Notes

Todos

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows project standards (link if applicable)
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future todos are captured in comments
• Visually tested in supported browsers and devices (see checklist below 👇)
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)
• Reviewers requested with the Reviewers tool ➡️

Testing checklist

Target Environment support

• Linux