Write the coordinate CF attributes according to the CRS

[snowman2]

https://pyproj4.github.io/pyproj/latest/build_crs_cf.html

The reading of the units from the coordinates will likely not be supported due to dependency on cf-units.

What can be improved/added:

1. Writing coordinate systems (projected versus geographic instead of by coordinate name)
2. Finding x_dim and y_dim based on searching through the CF coordinate attributes.