* audout: Implement GetAudioOutBufferCount, GetAudioOutPlayedSampleCount and FlushAudioOutBuffers
This PR implement audout service calls:
- GetAudioOutBufferCount
- GetAudioOutPlayedSampleCount
- FlushAudioOutBuffers
The RE calls just give some hints about no extra checks.
Since we use a totally different implementation because of our backend, I can't do something better for now.
SetAudioOutVolume and GetAudioOutVolume are fixed too by set/get the volume of the current opened track, previous implementation was wrong.
This fix#1133, fix#1258 and fix#1519.
Thanks to @jduncanator for this help during the implementation and all his precious advices.
* Fix some debug leftovers
* Address jD feedback