Better handle the dirty state of Airmap's flightplan

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)

Have different modes for the Airspace Widget (Plan/Fly)

Permit refactoring
QGCButton tweaks

Make all argument to AirMap queries based on what the screen shows (bounding rectangle and/or radius), respecting the limits imposed by AirMap.

AirspaceManager is now exposed by QGroundControlQmlGlobal instead of Vehicle (available all the time)

Fix sorting issues with QmlObjectListModel
Show airspaces in Plan View as well

Added an "unavailable" icon for when no vehicle is connected
Toggle restriction overlays (map) on/off based on the airspace widget being expanded/collapsed respectively

Handled "airspace visible" state (not done)
Adjusted restriction map items color and opacity
Added/Updated icons for airspace traffic
Adjust colors for text over maps

Users can select multiple rules concurrently. In addition, some are mutually exclusive. Add logic to handle this.

Adjust Airspace control text color to match changing background color

Added an "unknown" weather icon for when I get "valid" data and no icon

Eliminated flight widget "states"
Define flight widget top margin (plugin options)

Adjust colors
Remove unused image