[request] move background setting into wayfire instead of in wf-shell

[epsilon-0]

Currently, wf-shell handles setting the background, which is not the best desirable outcome, given that people would like to use wayfire but without wf-shell (thinking nwg-launchers).

This way I can have cool looking, sleek interfaces and based background even without wf-shell.

I don't know how hard/easy it is (so not the most important feature) but I want to just put it out there.

[soreau]

I've written a wallpaper plugin that loads random images from the internet for each workspace. It could be adapted to support loading files/directories like wf-background.

[ammen99]

I would also not be against a PR which makes wf-background a submodule of wf-shell, so that you could also install it separately if you wished to.

[epsilon-0]

I would love it if it becomes a part of wayfire. :heart: