Updates to gtfs spec changes - front end UI fields only

[landonreed]

We need to update the editor to conform to recent GTFS spec changes (full list of changes is here).

**This PR is only relating to the form fields

Agency.txt

• show validation warning when agency_id is missing for 2 or more agencies (and daylight the error message from the server if possible)

Stops.txt

• stop_lat/stop_long should be optional if location_type is greater than 2
• add new location types (Station, Entrance/Exit, Generic Node, Boarding Area)
• Stop_name should be optional if location_type is greater than 2
• platform_code (New field)
• needs investigation wheelchair_boarding (Type change from String to Int) was needed on the back end, is there a change on the front end needed?
• needs investigation - zone_id
• needs investigation - parent_station
• needs investigation - wheelchair_boarding

Routes.txt (but edited in PatternStops.js)

• continuous_drop_off (New field)
• continuous_pickup (New field)
• needs investigation - route_sort_order may need better support

Stop_times.txt

• continuous_drop_off (New field)
• continuous_pickup (New field)
• needs investigation - Arrival/departure times (needs investigating)

Trips.txt

• shape_id (update) - The continuous fields should be disabled if there is no shape.

Fair_attributes

• needs investigation - agency_id

Shapes

• needs investigation - major validation gaps

Feed_info.txt

• feed_contact_email (New field)
• feed_contact_url (New field)
• default_lang (New field)
• needs investigation - may need alignment

Translations

• needs investigation - Needs update for new file

Attributions

• needs investigation - attribution_id - Needs update for new file

Validation is handled in: https://github.com/ibi-group/datatools-ui/blob/dev/lib/editor/util/validation.js