Better handle the dirty state of Airmap's flightplan

The "Now" button now sets a "now" flag instead of adjusting the start time. Once the flight is created, the actual "now" time is set for flight start time.
The button is also exclusive. Once set, the start time slider is hidden as it becomes irrelevant.

If briefing evaluation returns no authorization, assume none is required. This is reflected in the UI as "Authorization Not Required".

Remove delete flights and add "End" active flight instead
Work on flight geometry (flight list)

Implementing authorization management

Flight management with date range, delete flights.

Cleaning up old vehicle manager and getting it ready to actually provide services for a vehicle (flight management)
Added submit flight plan
Added update flight plan
Disable flight features as these don't seem to be quite working (values must be initialized and validated before submission as backend doesn't validate and the objects don't initialize their members)

Permit refactoring
QGCButton tweaks

Collect rulesets from briefing

Moved flight planning away from "Flight Management" to its own class. Planning does not need a connected vehicle.