Home Location (HL) support

PX4 does not support setting HL from UgCS. HL is always automatically set to the current location when the vehicle is armed.
UgCS is able to read the current HL from the vehicle and display it on the map.

Warning!!!
Route waypoint altitudes are calculated based on HL altitude. Thus it is crucially important to launch
the vehicle from the planned HL. When operating in an area with variable terrain altitude make sure the
home location is specified correctly in the mission before uploading.

Note: Safest way to set the correct HL is to set it explicitly at the current vehicle position.

Vehicle behavior (land or do not land) after returning to Home Location depends on the autopilot configuration.