Show wheelchair accessibility for a stop

[barbeau]

Summary:

We'd like to be able to show wheelchair accessibility for a stop. This is similar to what was shown for StopInfo (#103), but defined by GTFS (see “wheelchair_boarding”):
https://gtfs.org/reference/static/#stopstxt

This allows you to model basic accessibility at the stop level (both for station stops and normal stops). Regions need to first provide this info via their GTFS, and the OBA API also needs to support it.

Google Maps shows this as "Station is accessible":

Steps to reproduce:

Tap on a stop

Expected behavior:

Show me if that stop is accessible

Observed behavior:

No such information exists

[Chay2203]

I would love to work on this issue @barbeau, could you please assign this to me :)