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.

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

This time to handle correctly updating plan/fly view when plan changes

Fixing the telemetry RSSI indicator.

Plus low battery announce changes