Uses the previously merged denoising crate (and fixes a bug in it that
snug in during refactoring) to add denoising to the microphone input. 

Adds automatic volume control for microphone and output.

Prepares for migrating to 16kHz SR mono:
The experimental audio path now picks the samplerate and channel count depending on a setting. It can handle incoming streams with both the current (future legacy) and new samplerate & channel count. These are url-encoded into the livekit track name

Release Notes:

- N/A