Update /vehicles to parse more information

We match live tracking data to data at vehicles:
https://realtimetcatbus.availtec.com/InfoPoint/GTFS-Realtime.ashx?&Type=VehiclePosition&serverid=0&debug=True

If we include debug=True, this is a JSON view-- however, if you check vehicles.py, we parse it in protobuf.

The problem is, I only recently started parsing this, and we're actually missing some info (not crucial though). I've only included the bare min.

The task is to update the entity_dict in vehicles.py:
entity_dict[vehicle_id] = {
"vehicleID": vehicle_id, # new!
"bearing": bearing,
"congestionLevel": congestion_level,
"latitude": latitude,
"longitude": longitude,
"routeID": route_id,
"speed": speed,
"timestamp": timestamp,
"tripID": trip_id,
}

to add more fields that can match the fields we already have but that we're just giving default values for in the PR below.

Highly recommend that you look at https://github.com/cuappdev/ithaca-transit-backend/pull/305 to get more ideas on what other information we can be parsing to provide the empty data that we are just giving default values for.