[AQTapDemo] fix status error -50 when starting the audio queue

[BlueRiverInteractive]

It seems that without calling enqueueBuffer this error doesn't happen but it is necessary to make the audio queue playback the streamed audio.

[BlueRiverInteractive]

We should be able to modify this sample to use MTAudioProcessingTap and AVFoundation streaming things. Event though AudioQueueProcessingTap hasn't been deprecated, it seems MTAudioProcessingTap + AVFoundation is now the preferred way to do these kind of things.