Ongoing fixes and improvements, transient suppressor is gone. Also,
dropping isac because it doesn't seem to be useful, and is just build
system deadweight now.
Upstream references:
Version: 131.0.6778.200
WebRTC: 79aff54b0fa9238ce3518dd9eaf9610cd6f22e82
Chromium: 2a19506ad24af755f2a215a4c61f775393e0db42
Since we cannot rely on the API to be stable upstream, let's start
making the pkg-config, library, and include dir have a version suffix.
This will allow different downstream projects depending on us to
independently switch versions without packagers having to jump through
hoops.
This new lib contains the bare minimum to implement an iSAC encoder and
decoder.
The webrtc files have been copied from the revision as the existing
imported files (c8b569e0a7ad0b369e15f0197b3a558699ec8efa).
