Request to add workspace widget suport for niri

[awawartemis]

I've just installed and set-up the wm niri, and noticed the workspaces widget doesn't work with it (not that I would expect it to). I've looked at creating my own plugin for that, but I really don't have the time nor motivation (nor, tbh, the skill) to do that, so I would really appreciate if you looked into it. The best way of getting workspace info out of niri seems to be running niri msg --json workspaces, which returns something that looks like:
[{"id":3,"idx":2,"name":null,"output":"eDP-1","is_active":false,"is_focused":false,"active_window_id":null},{"id":1,"idx":1,"name":null,"output":"eDP-1","is_active":true,"is_focused":true,"active_window_id":33}]