Use MPAS-Tools for great circle distance in cosine bell tests

[cbegeman]

This PR replaces the great circle distance computation in cosine_bell with that in MPAS-Tools. It is based on https://github.com/E3SM-Project/polaris/pull/126.

Checklist

• [X] API documentation in the Developer's Guide (api.md) has any new or modified class, method and/or functions listed
• [X] Documentation has been built locally and changes look as expected
• [X] Testing comment in the PR documents testing used to verify the changes User's Guide has been updated Developer's Guide has been updated New tests have been added to a test suite

[cbegeman]

Testing

The icos cosine_bell case has been run and it has machine-precision level diffs with main due to the great circle computation.

[cbegeman]

@xylar This is now rebased on https://github.com/E3SM-Project/polaris/pull/126 and ready for review, though you can wait until after that one is merged.

[xylar]

@cbegeman, I'm happy to review this once it gets rebased onto main.

[cbegeman]

@xylar It's rebased. Thanks for reviewing!

[xylar]

Please merge when you're reandy.

[cbegeman]

@xylar Thank you for reviewing!