Fix sizeToContents support

Support both relative and absolute FOLL_ALT_TYPE

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

Switch to using BATTERY_STATUS for battery info

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

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

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

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

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

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

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

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

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

Fix video initialization - VideoReceiver did not start because sink was not created because videoBackgroundComponent was not loaded on startup if video was disabled

Allow developers (or advanced users) to override UI settings - quite useful if you set your debug settings in QtCreator and do not depends on QGC settings state (they are reset to default sometimes, for example)