After the region type and region are selected, show a map of the choices

[shansen5]

Let the user see the counties, zip code boundaries, congressional districts, as in the Sunrise notebook.

[Frijol]

More context:

The Cross-Program Notebook (https://colab.research.google.com/github/edgi-govdata-archiving/ECHO-Cross-Program/blob/main/ECHO-Cross-Programs.ipynb) lets you select various types of region for analysis. Cell 2 asks you for a type of region; Cell 3 asks for a state. Cell 4 then asks which region you would like to select from that region type within that state area. It would be great to show users visual boundaries on a map to show the available areas.

We already have the geojson boundaries and use Folium in the Notebook, so this should be a pretty quick feature to add!

I think the ideal UX would be a zoomable map that shows borders between regions, then labels and transparently highlights each region on hover.

[Frijol]

There is code towards this already that @ericnost worked on in get_spatial_data and show_map in https://github.com/edgi-govdata-archiving/ECHO_modules/blob/reorganization/class.py