Pop-up notifications: support auto-dismissing notifications with an animated timer bar

[kevinaboos]

Currently, Popup notifications must be manually closed by the user, so I have been reluctant to use them a lot because that is an annoying UX pattern.

We should also support notifications that are automatically dismissed after a particular timeout (which would be set by the creator of the notification when enqueueing it).

Inspired by another service I use, we should also animate that timeout with a vertical progress bar. Note that we would still want to show a close button, in order to allow the user to close it before the timer completes.

See an example below:

Screen.Recording.2025-03-12.at.12.22.48.PM.mov

[Guocork]

I will enhance the widget, Pls assign to me.

[Guocork]

fix the issue by #462