refactor(fs): Move FSUIPC from fscommon to FS9

With default settings, FSUIPC was not really used
by FS simulators (except FS9) as the transponder
mode readout was done with SB offsets through SimConnect.
For simplification, this removes FSUIPC from fscommon and moves it to FS9.
Therefor this also removes the option for FSX/P3D users to toggle FSUIPC.

src/plugins/simulator/fsxcommon/simulatorfsxcommon.h

@@ -480,10 +480,6 @@ namespace BlackSimPlugin::FsxCommon
         //! \threadsafe
         void updateOwnAircraftFromSimulator(const DataDefinitionClientAreaSb &sbDataArea);
 
-        //! Update from FSUIPC
-        //! \threadsafe
-        void updateOwnAircraftFromSimulatorFsuipc(const BlackMisc::Aviation::CTransponder &xpdr);
-
         //! An AI aircraft was added in the simulator
         bool simulatorReportedObjectAdded(DWORD objectId);