FlightTask: fail activation if required states are not available

src/lib/FlightTasks/tasks/FlightTaskAuto.cpp

src/lib/FlightTasks/tasks/FlightTaskManual.cpp

src/lib/FlightTasks/tasks/FlightTaskManual.hpp

src/lib/FlightTasks/tasks/FlightTaskManualAltitude.cpp

src/lib/FlightTasks/tasks/FlightTaskManualPosition.cpp

src/lib/FlightTasks/tasks/FlightTaskManualStabilized.cpp

src/lib/FlightTasks/tasks/FlightTaskOffboard.cpp

src/lib/FlightTasks/tasks/FlightTaskOrbit.cpp