[feature] wireplumber: ability to list sinks and change the default sink

[kvikshaug]

An idea for the wireplumber module: On click, get a dropdown which lists all sink devices and lets you select another one as the default.

My use case is that I quite often need to change the default sink, and use pavucontrol to do so. Doing it with 2 clicks from the waybar instead would be really nice.

It's currently possible to bind a click to a script which uses wpctl to iterate and change the device, or even just open pavucontrol or some other tool, but I think the nicest experience would be an integrated dropdown where you can list and select the wanted default sink explicitly.

[Penguin-Guru]

In that issue/request I related, I described this as dynamically selecting the module's mapped source/sink. The two ways I can imagine it are:

• A click event could be used to open a list of alternative sources and/or sinks to select for the module's mapping, like you suggested.
• Scroll events could be mapped to cycle through source and/or sink mapping options.

In either case, I think it would be useful to support limiting the scope/subset of mappable devices, to reduce selection options per module. This could be based on source/sink type, nodes currently connected/enabled, and/or possibly white and/or black lists of source/sink identifiers/labels that the user has defined for the module instance.