Refactor|Audio|Client: Moved high-level sfx playback interface to audio/system.cpp/h
Todo: Revise high-level playback APIs so that the low-level audio driver interface can be internalized within audio::System (if needed we can expose higher-level interfaces via some base classes defined at audio::System API level).
Refactor|Audio|Client: Moved high-level sfx playback interface to audio/system.cpp/h
Todo: Revise high-level playback APIs so that the low-level audio
driver interface can be internalized within audio::System (if needed
we can expose higher-level interfaces via some base classes defined
at audio::System API level).