FlightTaskAuto: add type that corresponds to triplet type
FligthTaskAuto: set all setpoints if invalid in xy
FlightTaskAuto: cast triplet type to WaypointType
FlightTaskAutoLine: class for px4 legacy auto
FlightTaskAutoLine: methods prototype
FlightTaskAuto: change sp to wp (=Waypoint)
add params
FlightTaskAutoLine: follow waypoints along line based on flight state