extract audio dumps

[fippo]

Since I just re-read https://webrtchacks.com/troubleshooting-unwitting-browser-experiments-al-brooks/ using a web page to extract (and play or even visualize) the AEC dumps would be great and this repository is moving towards this (but maybe it should be merged into the json dump importer)

The native tool is here: https://chromium.googlesource.com/external/webrtc/+log/master/rtc_tools/unpack_aecdump and the proto file is here: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/audio_processing/debug.proto