Add global palette object to QGroundControlQmlGlobal for generic usage

Added pass/fail/pending text colors to the QGC palette which default to standard text color. Added such that custom builds can override

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

Export color palette in formats that can be directly used by QGC and custom plugins (in addition to the original Json)
Tweak palette export UI

Restore QGC to its normal UI layout (buttons on toolbar)

Q_ENUMS is deprecated and should not be usued.
Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Changed (selected) mission item color to primaryButton instead of buttonHighlight
Adjusted some colors for better contrast
Removed a few JavaScript exceptions caused by the order of object destruction

Also updated some docs

Map control use different border color based on map type

Plus lots of other tweaks to ui for visuals

Controls respect QGCPalette settings. Also added test window.