Updated MAVLink to handle video stream types (auto discovery)

On desktop (Ethernet connection), the ground unit pushes UDP directly, which makes the use of an actual "Link" not possible. Instead, I've moved all of Taisync support to a "manager" owned by QGCToolbox.
Added a Taisync settings with some basics already wired and running.

ArduPilot option to not start mavlink streams

CP - If a metadata name is not found in the Json file, issue an error and exit. It would crash if let proceed.

Expose guided altitude settings. Rearrange Fly and Plan view settings.

Clarify Base Position Altitude frame of reference

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

Q_ENUMS is deprecated and should not be usued.

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

9 digit precision for lat/lon

Add support for specifying fixed RTK base position

Added support for qgcRebootRequired Fact meta data value.

Show the link indicator in the tool bar if two or more links are connected and at least one of them is a high latency link.
Show in the link indicator if a link is inactive.

This setting enables/disables the LinkIndicator toolbar in which the primary link can be chosen.

Automated preflight checklist: Initial commit. Note that this requires an autopilot firmware that writes the respective health flags in the SYS_STATUS mavlink message