Remove basemap dependency

[xylar]

The basemap package is no longer being maintained (see https://matplotlib.org/basemap/users/intro.html#deprecation-notice) and is becoming increasingly hard to install along with other conda packages (notably proj and pyproj).

I would like to remove it from compass. It is currently used in the following locations:
https://github.com/MPAS-Dev/MPAS-Model/blob/ocean/develop/testing_and_setup/compass/ocean/jigsaw_to_MPAS/coastal_tools.py#L19
https://github.com/MPAS-Dev/MPAS-Model/blob/ocean/develop/testing_and_setup/compass/ocean/jigsaw_to_MPAS/coastal_tools.py#L895-L896
https://github.com/MPAS-Dev/MPAS-Model/blob/ocean/develop/testing_and_setup/compass/ocean/hurricane/interpolate_time_varying_forcing.py#L11
https://github.com/MPAS-Dev/MPAS-Model/blob/ocean/develop/testing_and_setup/compass/ocean/hurricane/interpolate_time_varying_forcing.py#L99-L129

I think it should be possible to use cartopy for this plotting instead.

[xylar]

@sbrus89 (cc @pwolfram), would you be willing to help with this? It looks like maybe the current usage of basemap is in code you wrote.

[sbrus89]

@xylar, sure. I'd be happy to help. Sounds like moving to cartopy is the way to go.

[pwolfram]

@xylar, I believe we've purged this issue on our coastal branch. Can we please close?

[xylar]

I don't believe this has made it to ocean/develop yet, for example:
https://github.com/MPAS-Dev/MPAS-Model/blob/ocean/develop/testing_and_setup/compass/ocean/jigsaw_to_MPAS/coastal_tools.py#L19

@mark-petersen, since you aren't ready to merge ocean/coastal to ocean/develop how can we at least get #441?

[xylar]

Addressed by #441