Actually set the right properties on the source and sink.
Not quite right because the pulseaudio ROC has a sink-input or a
playback stream in pipewire.
See #1538
Virtual sinks and sources implemented with streams need to be grouped
with a driver node to be able to schedule. We don't have a way to let it
use a default driver so add it to the pipewire.dummy driver.
This fixes stalled pipe and other streams streams.
Fixes#1407