feat: add .urgent workspace css class

[Rodrigodd]

Allow highlighting a workspace which contains a window that triggered a urgent event, i.e., requests attention. In my case, I see it happens when I clink a link and it opens in a new tab on firefox, and when displaying a BEL character in some terminal emulators (at least in alacritty).

You can test it by running

sleep 1 && tput bel

in alacritty, and switching to another workspaces before the sleep expires.

I implemented it for both Sway and Hyprland. Sway keep track of a urgent flag for each client, and notify ironbar about changes. Hyprland or the other hand only contains a urgent event that triggers once, so I clean the urgent state of a workspace whenever it is focused.

[Rodrigodd]

Revised everything now. Fixed a typo in the docs, remove the dbg! usage, and fixed some non-formated code inside a macro.

[JakeStanger]

Thanks for this. This looks good, I'll test it when I can and will approve once I've confirmed it working as expected.

[yavko]

Looks fine to me

[JakeStanger]

Cheers, this looks good.

The next release will be bugfix-only, so I'm going to hold off merging for the time being. Once #748 merges, this will need to be slightly reworked, which is poor planning on my part. I'll pick that up to avoid creating you too much more work.