DRY the rest of the timeout logic that was still done in the subclasses back to the AbstractBubble class. Now the timeout is started when the notification is presented and resulting in longer bubbles. This also changes an possibly unwanted behaviour in the case of urgent notifications getting expired after hovering over them.
While here, also do a little of cleanup and preparation for Gtk4.
DRY the rest of the timeout logic that was still done in the subclasses back to the AbstractBubble class. Now the timeout is started when the notification is presented and resulting in longer bubbles. This also changes an possibly unwanted behaviour in the case of urgent notifications getting expired after hovering over them.
While here, also do a little of cleanup and preparation for Gtk4.