Georegion suggestion API

A new API that takes in a list of domains and a bounding multipolygon as input, and constructs a SoQL query to return georegions that match the given domains and intersect with the given shape. (A dataset with aggregated data about georegions has to be created in the new backend for this to work.)

Other misc changes:
- Removed the one-off SodaFountainClient implementation from Geospace and replaced it everywhere with references to the official one in soda-fountain-external
- Changed all /experimental routes to /v1