Add Avahi zeroconf publish module

Fixes #865 (closed).

Tested as below.

On PipeWire side,

pactl load-module module-native-protocol-tcp port=9999
pactl load-module module-zeroconf-publish port=9999

On the other PulseAudio/PipeWire side,

pactl load-module module-zeroconf-discover

PulseAudio version used during testing was 14.2.