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

• [x] 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

• [x] stop_lat/stop_long should be optional if location_type is greater than 2
• [x] add new location types (Station, Entrance/Exit, Generic Node, Boarding Area)
• [x] Stop_name should be optional if location_type is greater than 2
• [x] 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)

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

Stop_times.txt

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

Trips.txt

• [x] 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

• [x] feed_contact_email (New field)
• [x] feed_contact_url (New field)
• [x] 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