3-d spherical regridding and regridding to DSG feature types

[davidhassell]

Fixes #715 and #716

Notes

• dask_regrid.py: Added axis logic to cope with regridding 3-d input data to 1-d output data
• data.py: Fix bug when calculating output chunksizes
• field.py: Extend API for vertical regridding keyword parameters
• regrid.py:
  • Extend API for vertical regridding keyword parameters
  • Extended Grid dataclass for locstream and vertical regridding parameters
  • Added functionality to infer grids from DSG featureType fields
  • Refactored the creation of esmpy.Grid instances so that 3-d spherical grids are included without any extra special treatment
  • Added the createion of esmpy.Locstream instances
  • Added extra information to output weights filess (following what ESMF itself does)
• regridoperator.py: Included parameters for vertical and DSG regridding

[sadielbartholomew]

Thanks for the notes for review David. Is this ready for review now or shall I wait?

[davidhassell]

Good to go ...

[sadielbartholomew]

Just finalising some functional reviews, but here are my minor comments from eyeballing the code.

[sadielbartholomew]

I am happy with all of the functionality introduced/changed here. It works including for our work towards VISION goals, as discussed externally.

Thanks for addressing the feedback from my previous review set. Everything looks good to me, now, and the full test suite is passing locally.

There's one spurious line now in the changelog, but once that is removed, please merge.