Add spatial search in filters

[tdlowden]

Feature/what we're after

Allow users to filter by spatial features- bounding box and/or country/state/city names

Anticipated/hypothesized benefits

• users can look for datasets related to a region

Measurements/metrics

• [description of a thing that can be monitored or tested to measure and validate when the outcome has been achieved]

References/background

• [notes about desirable attributes or context for the epic]
• [links to previous research, possible routes to take, things that multiple stories will likely need to refer to]