Implements 'Airplane mode' feature to disable and enable bluetooth/ble
Adds airplaneMode as a non-persisted setting
Adds a setting menu for switching airplane mode on and off
Displays an airplane symbol on the Digital watch face and the
PineTimeStyle watch face when airplane mode is enabled
Always enables bluetooth/ble on boot (disable airplane mode)
Alphabetizes the settings menu options
Style cleanups
Closes#632
Don't use relative imports like `../foo.h` as those depend on the
relative position of both files. Rather than that use imports relative
to the `src` directory, which explicitly is part of the include
directories.
