NetCDF reader from TempestRemap format

**Is your feature request related to a problem? Please describe.**
We have a NetCDF writer, but not a reader. ClimaCoupler needs this information for e.g. land-sea masks and SST data.

**Describe the solution you'd like**
A function which takes:
- a ClimaCore space
- a NetCDF variable, and optional indices
and returns a Field on that space.

It should throw an error if the dimensions of the dataset are inconsistent.
It should correctly handle the "cgll" representation (e.g. by broadcasting duplicated values).

**Describe alternatives you've considered**
No distributed support for the time being.

**Additional context**