Add support/test silero VAD V6 #3450
Description
As released few weeks ago:
https://github.com/snakers4/silero-vad/releases/tag/v6.0
Improved quality;
v5 features and improvements kept;
16% less errors on noisy real-life data;
11% less errors on multi-domain validation;
Changed the training algorithm, ideally it should result in higher robustness;