message: mission: add mission clear
diff: @@ -618,8 +618,16 @@ Mission::Result MissionImpl::command_result_to_mission_result(MAVLinkCommands::R
  void MissionImpl::clear_mission_async(const Mission::result_callback_t& callback)
  {
  - UNUSED(callback);
  - // TODO: implement clear
  + _parent->mission_transfer().clear_items_async(
  + MAV_MISSION_TYPE_MISSION,
  + [this, callback](MAVLinkMissionTransfer::Result result) {
  + auto converted_result = convert_result(result);
  + _parent->call_user_callback([callback, converted_result]() {
  + if (callback) {
  + callback(converted_result);
  + }
  + });
  + });
  }
  void MissionImpl::set_current_mission_item_async(int current, Mission::result_callback_t& callback)
  