Dataman: Add write function to dataman cache.
RTL and mission have a new common base class mission_base. Both inherit from them and mission, RTL mission, and rtl reverse mission inherit from them and implement their desired functionalities. This simplifies the logic in mission as well as make the logic in rtl mission reverse and mission more readable.
Rtl mission reverse now functional again for VTOL flying back the mission and transitioning to MC at the home position.
Dataman cache has new write functionality to write to dataman while updating write item in its cache if necessary.
Dataman cache is now only updated when the respective module is active. Leads to a higher computation time once on activation, but decreases unnecessary cache updates when inactive.
