Rewrote editor to be performant enough to support typedown

The overloaded member signal just hit us, to use it is a pain
but the resuting code is faster and less error prone, so it's
still a good thing to do.

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

- Pervasive change to automatically connect to known board types
- Lots of additional changes along with this:
- More exposure of objects/properties to Qml
- Much restructuring in LinkManager and LinkManager clients

- Pervasive change to automatically connect to known board types
- Lots of additional changes along with this:
- More exposure of objects/properties to Qml
- Much restructuring in LinkManager and LinkManager clients

- Pervasive change to automatically connect to known board types
- Lots of additional changes along with this:
- More exposure of objects/properties to Qml
- Much restructuring in LinkManager and LinkManager clients

- select active vehicle
- arm/disarm
- select flight mode

Also:
- Remove unused code

Also much other cleanup/change

Plus more overall ui work

- New MissionManager
- Plumb MissionManager through MissionEditor
- Mission Editor supports get/set