Shorten meta data keys for smaller file sizes

Add support for Json file string translations

Remove BatteryFactGroup::cellCount support

Handle unreliable PX4 support of BATTERY_STATUS

Change all internal values to double to NaN can be used from unavailable values

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

Move battery.percentRemainingAnnounce to Qml Global

The static Fact was causes problems with Qml

Removed incorrect Vehicle.altitudeWGS84

Plumb through initial object mode on Vehicle