Navigator simplify mission

src/modules/navigator/datalinkloss.cpp

src/modules/navigator/enginefailure.cpp

src/modules/navigator/mission.cpp

src/modules/navigator/mission.h

src/modules/navigator/mission_block.cpp

src/modules/navigator/mission_block.h

src/modules/navigator/mission_feasibility_checker.cpp

src/modules/navigator/mission_feasibility_checker.h

src/modules/navigator/rcloss.cpp