Allow several Audio devices when using Jack

[nodens]

When using Jack (or pipewire), one can see any jack client and interface in the list of interface. It'd be nice to be able to have several of them on the graph, instead of only one input and output. If using pipewire via jack, one can even handle several audio interface.

It doesn't have to be the full graph: be able to manage audio routing between selected apps and graph would actually be better than using the whole graph IMO: there are other apps for that, but Element is very good at showing routings, and the patch bay matrix view is actually something I'm missing in most jack session managers.

This is related to #808, I guess, but I'd like to be able to use audio the same way.