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

An rather unfruitful attempt at consolidating Advisories and Airspaces (they are both arrays of Airspaces). No such luck as they vary wildly. In the end, I'm now exposing the restrictions (Polygons) directly (and inherently) instead of copying them.
Tweaked polygon overlay colors and borders.

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

All settings wired and persistent
Cleanup non Airmap builds

Move all airmap related stuff to its own directory

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

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

- popup don't work with map
- improve popup visible logic

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

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

- 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)

Clarify the title of the "Video Stream" panel (instead of just "Video")

On large/high DPI screens, the whole UI scales nicely when increasing the
font size, except for the attitude widget, that was limited to 200 pixels.

For whatever reason, showing the dialog through a function causes a crash in QML (undebugable--new word!)

Internet available now has a signal

Also rename QmlPageInfo to QmlComponentInfo to cover more use cases