Add regionNames coordinate to NetCDF output with "standard" region names

[xylar]

Two MPAS-Ocean analysis members use ocean regions that are hard-coded and for which no coordinate array or other metadata is provided. This merge adds both regionNames and regionShortNames coordinates to datasets that use these standard regions. Here, we also rename nOceanRegionsTmp to nOceanRegions because the Tmp suffix is confusing and needless.

All analysis using the hard-coded ocean regions has been updated. The config option regions has been renamed to regionShortNames for clarity, and plotTitle has been renamed to regionNames, since these long names are more rightly the names of the regions.

This should help folks that wish to use the NetCDF output from MPAS-Analysis for their own plots.

Checklist

• User's Guide has been updated
• API documentation in the Developer's Guide (api.rst) has any new or modified class, method and/or functions listed
• Documentation has been built locally and changes look as expected
• Testing comment in the PR documents testing used to verify the changes

Fixes #1065

[xylar]

@golaz, just a heads up that the confusing output you found for the OHC anomaly should be fixed in the new Unified, assuming I can get this reviewed and added very soon.

[xylar]

Testing

I rand the test suite and all tests seem to have run successfully:
https://web.lcrc.anl.gov/public/e3sm/diagnostic_output/ac.xasay-davis/analysis_testing/chrysalis/add-ocean-region-names-coord/

However, the web portal is basically unusable today so I can't see if the output looks right.

[xylar]

@milenaveneziani, would you have time to look this over in the coming week? I mostly want to make sure you're conceptually okay with the changes but if you want to look through the code changes and/or the output from the test suite, feel free. Output is in:

/lcrc/group/e3sm/ac.xylar/analysis_testing/chrysalis/add-ocean-region-names-coord

[milenaveneziani]

Looks great @xylar: thanks for pinging me. I just noticed a couple of typos in the comments (look for 'shrot').

[milenaveneziani]

Approved based on code inspection.

[xylar]

Thanks @milenaveneziani, I'll fix those typos.