MongoDB is not yet required, as we currently only have unit tests

This allows acquiring location data from stops, unavailable from HTML data source

…le to package; Validate at least one stop with location when getting multi-stop map

Write cache of queried Google Maps & Streetview pictures with metadata. Pending implementation of reading before requesting Google Maps API, and returning cached pictures; plus integration with Telegram File IDs.

Add aliases to routes, using plurals as standard ways (e.g. "/stops/{stop_id}" instead of "/stop/{stop_id}"), but supporting old form

Rename stops-tags relation header on multi-stop map endpoint

Avoid conflict with /stops/map endpoint being handled as a /stop/{stop_id} endpoint.Endpoints may end up being refactored in the future

Instead of defining the TTL on the Mongo cached-stops index, define the TTL to 1 second of expiration, while a new datetime field on documents indicate when the document shall expire.