pipewire-pulse: add module-switch-on-connect
module-switch-on-connect sets the configured default sink/source whenever suitable new sink/sources appear.
This should give the same behavior as Pulseaudio's module.
This module exists mainly to provide a workaround e.g. for desktop environments such as XFCE, whose mixer applications try to manage the default devices assuming fully PA-like behavior, breaking default pipewire output switching.
Didn't implement only_from_unavailable --- not clear that's useful here...
Edited by P V