Feature Request: Adding ViSQOL/MOS scores for audio quality measurements

[suyash-ls]

Currently, the utility allows us to observe the Inbound and Outbound audio stats. ViSQOL/MOS will allow the developers and teams to understand the audio performance of their application against a objective score.

ViSQOL - Perceptual Quality Estimator for speech and audio (https://github.com/google/visqol)

I've been using manually compiled binary of ViSQOL to obtain the performance of my platform. Having this as part of WebRTCPerf would be very convenient.