Initial suggestion for FCO schemas

This is intended to support data capture and display for:

- number of appointments booked
- number of appointments booked, at consular level
- appointments by consular service type
- appointments by consular service type, at consular level
- appointments by channel, overall and at consular level
- number of no-shows for appointments, overall and at consular level
- usage of available hours, overall and by consulate
Merge pull request #212 from alphagov/feature/fco-jsonschema

Initial suggestion for FCO schemas