WINTERMUTE: Introduce WMEGameDescription

I aped what has been done with AGS: in engines/agi/detection.cpp, adding
a struct that includes ADGameDescription at the beginning.

This is also recommended in advancedDetector.h
WINTERMUTE: Use target executable info to trigger killAllSounds
WINTERMUTE: Do away with redundant WGF_NO_KILLALLSOUNDS

Also, this is kind of not considered a "workaround" anymore - more of an
/engine feature/