navigator: use new Param class

src/modules/navigator/datalinkloss.cpp

src/modules/navigator/datalinkloss.h

src/modules/navigator/enginefailure.cpp

src/modules/navigator/enginefailure.h

src/modules/navigator/follow_target.cpp

src/modules/navigator/follow_target.h

src/modules/navigator/geofence.cpp

src/modules/navigator/geofence.h

src/modules/navigator/gpsfailure.cpp

src/modules/navigator/gpsfailure.h

src/modules/navigator/land.cpp

src/modules/navigator/land.h

src/modules/navigator/loiter.cpp

src/modules/navigator/loiter.h

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/navigator.h

src/modules/navigator/navigator_main.cpp