Support switching profiles

[hackel]

I'm basically just pulling in https://github.com/anduchs/audio-output-switcher/issues/5 since this seems to be the most active fork. Currently this extension doesn't show any audio devices for me, other than the default. gnome-control-center seems to parse audio devices differently, including what in pavucontrol are listed under Configuration / Profiles.

There was already an attempt to support this in the original ports2 branch that people claimed was working 5 years ago, if anyone feels adventurous!

https://github.com/anduchs/audio-output-switcher/compare/ports2