Multi-Vehicle Start/Pause Fixes

Prevent clicks going through top level items

Remove unused code

The X-UAV Mini Talon is a V-Tail plane. This commit adds the
new group "Plane V-Tail" together with a svg image for the
new group.

Fix terrain NaN making it all the way to Planned Home altitude.

Fixed the core MAVLink receiver. Among other things, it wasn't accounting for fragmented messages.
Fixed code that monitors messages received (and lost)
Added a section within the MAVLink panel to show the current status (for the current vehicle)
Remove some old, unused exposed interfaces

Also fixing some c++ errors within commented off code as the localization engine was getting confused by it.

Limit all queries to areas smaller than 500km^2. If an area of interest is greater, clip to 500km^2 centered on current ROI's center.
Removed the identifier "Airmap" from error messages coming from Airmap.
Added a clipping function to QGCGeoBoundingCube (clip polygon to given area)

Fixes https://github.com/mavlink/qgroundcontrol/issues/6770

Fixes https://github.com/mavlink/qgroundcontrol/issues/6770

Fix resume mission item count bug

Support GuidedActionsController logging

Update to setCoordinate no longer changing altitude

Removed setCoordinate support to reduce confusion

setCoordinate was screwing up altitude/param7 syncronization

I have no idea how this was building elsewhere at all.

Expose root plan keys

Back up further from end of file to handle more cases