transition alignment will force heading now and go to RTL if it cannot reach it in time, handle mission failure correctly, reset after mission update, issue message with actual problem

src/modules/navigator/mission.cpp

@@ -219,6 +219,8 @@ Mission::update_onboard_mission()
 
 		// XXX check validity here as well
 		_navigator->get_mission_result()->valid = true;
+		/* reset mission failure if we have an updated valid mission */
+		_navigator->get_mission_result()->mission_failure = false;
 		_navigator->increment_mission_instance_count();
 		_navigator->set_mission_result_updated();
 
@@ -263,6 +265,10 @@ Mission::update_offboard_mission()
 				_navigator->get_vstatus()->condition_landed);
 
 		_navigator->get_mission_result()->valid = !failed;
+		if (!failed) {
+			/* reset mission failure if we have an updated valid mission */
+			_navigator->get_mission_result()->mission_failure = false;
+		}
 		_navigator->increment_mission_instance_count();
 		_navigator->set_mission_result_updated();
 
@@ -510,6 +516,7 @@ Mission::set_mission_items()
 				_navigator->get_global_position()->lon,
 				mission_item_next_position.lat,
 				mission_item_next_position.lon);
+			_mission_item.force_heading = true;
 		}
 
 		/* yaw is aligned now */