Create `/map` namespace and move `/data-sources-map` to there

[maxachis]

Context

Currently, the data-sources/data-sources-map endpoint is online, but there are a few issues:

1. The /data-sources/data-sources-map endpoint overlaps with the /data-sources/{resource_id} endpoints, which may not be best practice
2. The endpoint requires API or JWT key authorization, but this is not displaying in the API documentation, possibly because of 2.
3. Describing it as "data sources" is somewhat misleading, because the data is a product of both data sources and agencies (specifically, it provides the data sources associated with agencies which themselves have non-null latitude and longitude

Requirements

• Move this to its own /map namespace, where it can roam free and unencumbered.

Tests

• Tests will need some modification but otherwise not be affected

Docs

• API documentation will need updated

Open questions

• Should we rename it to something else?

[maxachis]

Eh, never mind, not a big enough deal once I figured out the bug