Add Curvilinear Support

[stephenworsley]

Adds support for either the source or target grid to be curvilinear (described by 2d coordinates).

[codecov[bot]]

Codecov Report

Merging #125 (7cd77d7) into main (e528cbf) will increase coverage by 0.24%. The diff coverage is 99.70%.

@@            Coverage Diff             @@
##             main     #125      +/-   ##
==========================================
+ Coverage   98.85%   99.10%   +0.24%     
==========================================
  Files          14       14              
  Lines         699     1005     +306     
==========================================
+ Hits          691      996     +305     
- Misses          8        9       +1     

Impacted Files	Coverage Δ
esmf_regrid/schemes.py	98.24% <97.56%> (-0.70%)	:arrow_down:
esmf_regrid/_esmf_sdo.py	96.96% <100.00%> (+1.13%)	:arrow_up:
esmf_regrid/tests/unit/_esmf_sdo/test_GridInfo.py	100.00% <100.00%> (ø)
...sts/unit/schemes/test_ESMFAreaWeightedRegridder.py	100.00% <100.00%> (ø)
...egrid/tests/unit/schemes/test__cube_to_GridInfo.py	100.00% <100.00%> (ø)
.../schemes/test_regrid_rectilinear_to_rectilinear.py	100.00% <100.00%> (ø)

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[jamesp]

Looks good to go 👍

Things to do after this is merged:

• [x] Bump version number to 0.3.0 and tag as release
• [x] Add 0.3.0 changes to the changelog
• [x] Bump version number to 0.4.dev0.
• [ ] schemes.py#L36 needs an issue to track the additional checks required. Add to backlog.