remoting,pipewire: Use the connector and the output name for the head name

Makes the client's life much easier to identify between multiple remote outputs. xdg_output is advertising (in later versions) the head name, but in case we have different plug-ins or multiple remote outputs created, it would only repeat/advertise the same name for the same (remoting) output.

This instead uses a string that uses both the connector and name to derive a more easier identifier a client can choose from.

Signed-off-by: Marius Vlad marius.vlad@collabora.com