MPC auto - Add MPC_YAW_MODE: towards waypoint (yaw first) mode. This mode ensures that

the vehicle yaws towards the next waypoint before accelerating. This is
required for drones with front vision and aerodynamic multicopters such
as standard vtol planes or highspeed multirotors.

src/lib/FlightTasks/tasks/AutoLine/FlightTaskAutoLine.hpp

@@ -66,4 +66,5 @@ protected:
 private:
 	void _setSpeedAtTarget(); /**< Sets desiered speed at target */
 	float _speed_at_target = 0.0f;
+	bool _position_locked{false};
 };