This allows for testing issues found on high dpi screen without needing
a high dpi screen. it does this by doubling the font sizes.

Plus more overall ui work

- New MissionManager
- Plumb MissionManager through MissionEditor
- Mission Editor supports get/set

- Only show video option if supported
- Persist settings
- Show/Hide/Add items correctly

While at it, fixed an issue with builds that have video streaming disabled.

- Restructured a number of MissionItem properties as well

When on Joystick config page:
- Not calibrating: If joystick is enabled, joystick messages should
continue to go to vehicle