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

Break apart string of classes into their own files as all in one file became unwieldy
Expose Airspace data in a QML ready format
Split global Airspace from AirMap (Only now I figured out the reason for the pure virtual root classes)
Refactored a bunch of things to make it consistent and/or obvious

Move all airmap related stuff to its own directory

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Needed to support different indicators for advanced mode

- add multi-vehicle support: each vehicle has now a per-vehicle AirMap
  object that takes care of flight creation, traffic & telemetry
- add a base class API layer so that the interface between QGC and the
  AirMap implementation is clear, and easier to change
- removes polygon upload to vehicle (needs a better solution)

Make AirMapController as part of a Vehicle rather than a creatable QML instance. This is ultimately linked to a vehicle and not the view. Eventually a lot of the code currently in AirMapManager will have to come here as well so the data persists with a vehicle. AirMapManager should only handle the global aspects.
Added a temporary indicator right below the toolbar. It's only visible if a permission (of any kind) exists. I need to understand better how this works before coming up with a more permanent solution.
Restored toolbar to its original state (brand logo and whatnot)

Fix merge issues

This extension introduces a complete version handshake mechanism which will detect wether the vehicle AND the complete link / routing infrastructure support MAVLink 2. If they do, QGC will switch to the highest protocol version supported by all connected vehicles. If a new vehicle connects, it will re-negotiate the highest possible version. This means that we error on the side of compatibility, which later can be easily changed.

Remove/comment off debug output pollution