Add Current Waypoint Option for SITL aircraft

[UASOP]

Tell us a bit about the feature:

• What problem does it solve? The current state is that PX4 SITL aircraft does not have the current waypoint option available when connected to QGC, this is helpful when monitoring SITL flights that are used for doing a test run of a flight plan or training students on an airframe that is using PX4 as they will want to know which waypoint the aircraft is heading to in case there is a high degree of overlap in the waypoints, such as in a survey grid mission test plan for a large area with close paths and a large area. There are other examples where this feature would be useful as well.

• What does it do? The feature would allow mavlink messages that are communicated from PX4 SITL to QGC to enable the updating of current waypoints in QGC.

• What flight stacks must it work with? (All, PX4, ArduPilot) PX4, but I also have not tried testing to see if it is one Ardupilot yet, which would be a good addition for airframes that use ardupilot as well. I will respond back here with an update for the ardupilot sitl.

• Relevant vehicle types? (All, multirotor, fixed-wing, VTOL, submarine, etc.) All vehicle types.

• Are there other systems that have this feature? I have not been able to check on that but will see if Ardupilot sitl supports this.

• What communication/integration standards does the feature rely on (e.g. MAVLink commands etc.) From my basic understanding, I believe this would need to include a mavlink message for updating QGC on what waypoint the SITL aircraft is going to.

First time posting in the QGC repository, please let me know if there is any other further information needed, please and thank you! :)

[DonLakeFlyer]

I assume you are asking that the current waypoint of a mission is made available for display in instrument panel. Is that correct?