This PR properly compiles cython to remove pyximport

[AreWeDreaming]

Description

This modifies the setup.py to compile the Cython code OMAS uses

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Other (please describe):

Testing

There is a new tests that checks if cython was compiled properly

Pre-Merge Checklist

• OMFIT has been tested with this OMAS version and you will create a PR on OMFIT that updates the OMAS submodule once this has been merged.
• Version number has been incremented if this is a major modification or important bug fix
  • To increment the version: Edit the version number in omas/version file
  • Follow semantic versioning: MAJOR.MINOR.PATCH (e.g., 0.94.2 → 0.94.3 for bug fixes, 0.94.2 → 0.95.0 for new features)
  • A GitHub release will be automatically created when this PR is merged if the version number has changed

Additional Notes

[smithsp]

If this compiles/builds, then let's merge? Or do we need a dedicated OMFIT branch to test this?