feat: add shapely support

Add support for converting Geometry objects to shapely.geometry objects and for converting Features to geopandas.GeoDataFrame.

[x] Dependencies install correctly in a clean environment and code executes;
[x] Test coverage extended; created tests fail without the change (if possible);
[x] All tests passing;
[x] Commits follow a type convention (e.g. https://gist.github.com/brianclements/841ea7bffdb01346392c#type);
[x] Extended the README, documentation and/or docstrings, if necessary;

transition-zero / tz-client