Add module systemd-failed-units to monitor failed systemd units

[oxalica]

This module monitors the number of failed systemd units and can warn user if there is something going wrong. It's especially useful for periodic services.

Currently only the count is monitored and displayed, and there's no tooltip. It's nontrivial to get the actual failed unit names and it seems to require enumerating all units and then filter, which would be too CPU intensive to be done frequently.

Related but not equivalent to #1187.

[Alexays]

LGTM!
Can you also add a new entry in the github wiki?

[oxalica]

Can you also add a new entry in the github wiki?

Added https://github.com/Alexays/Waybar/wiki/Module:-Systemd-failed-units

[HilkopterBob]

ive tried for days to use it. Please edit the wiki so its visible its a draft and not published and maybe remember that for future features/wiki articles

[oxalica]

@HilkopterBob

Please edit the wiki so its visible its a draft and not published

I tried in a private browser session without signing in GitHub and the page is public visible. There's no "draft" or anything relevant state, button or toggles in the edit page. The link above is also working publicly. Maybe you need to refresh your browser cache and try again? Or could you elaborate why you think it's "draft state and not published" and how to fix it?

[HilkopterBob]

Sorry, i meant that the feature isnt published yet and i think that should be visible in the wiki article.
Sorry for the miscommunication.

[oxalica]

Sorry, i meant that the feature isnt published yet and i think that should be visible in the wiki article.

Ah, that makes sense. I added a warning to the wiki. Thanks.

[andyrtr]

Is there a way to style the colour of format-ok/format in style.css to make the small but helpful notification more visible or would this require additional changes to the source?