Add a visual indication to Favicon/Tab

[Git'Fellow]

This is what we get when a monitor is down in a full tab. Howhever, if the tab is pinned on browser, we have no visual indication.

Uptime-Kuma project has implemented this, for reference (here both tabs pinned, side by side, where both have 2 monitors down):

[Prince Khunt]

Hi

I have tried to implement this in a PR #977

[Git'Fellow]

Please allow me to specify that favicon is only updated if inside the project where a monitor is down.
If on "All projects" tab, favicon is not updated, and it should be IMO.