Moved most of the contents of FAudioDevice::FreeResource to USoundWave::FreeResources so that we can be sure that all memory is cleared up during teardown.
Removed FreeResource function from some subclasses of audio device, as they weren't doing anything different than the base one.
Also removed ListSounds function from these same classes as that seems to have fallen behind current base class version and isn't used anyway.
Removed platform specific audio buffer storage so that there isn't confusion about which is being used and ensured that casts are used when necessary.
Fixed compile issue with STAT_AudioResourceCreationTime for HTML5.
[CL 2109273 by Matthew Griffin in Main branch]
Followed pattern set out by texture streaming so that each chunk of audio data resides in its own bulkdata struct. It is currently possible to split audio into chunks when SoundWaves are marked for streaming but there is no way of doing this exposed at present.
Changed the parameters of FAudioDevice::GetRuntimeFormat so that the relevant SoundWave must be passed in, to allow for different formats for individual sounds/streaming options.
USoundWave::FreeResources no longer resets the NumChannels as it is unnecessary and causes sounds to be unable to play after the OGG data is flushed when attempting to switch to OPUS.
[CL 2099012 by Matthew Griffin in Main branch]
- catch up with changes in core Audio ( add relevant virtual functions ).
- clean up logging.
#codereview peter.sauerbrei
[CL 2086334 by Ankit Khare in Main branch]
