message: mission_raw:  mark two methods static
diff: @@ -30,11 +30,12 @@ public:
  private:
  void process_mission_ack(const mavlink_message_t& message);
  - MissionRaw::Result convert_result(MAVLinkMissionTransfer::Result result);
  - MissionRaw::MavlinkMissionItemInt
  - convert_item(const MAVLinkMissionTransfer::ItemInt& transfer_item);
  - std::vector<std::shared_ptr<MissionRaw::MavlinkMissionItemInt>>
  - convert_items(const std::vector<MAVLinkMissionTransfer::ItemInt>& transfer_items);
  +
  + static MissionRaw::Result convert_result(MAVLinkMissionTransfer::Result result);
  + MissionRaw::MavlinkMissionItemInt static convert_item(
  + const MAVLinkMissionTransfer::ItemInt& transfer_item);
  + std::vector<std::shared_ptr<MissionRaw::MavlinkMissionItemInt>> static convert_items(
  + const std::vector<MAVLinkMissionTransfer::ItemInt>& transfer_items);
  struct MissionChanged {
  std::mutex mutex{};
  