Tentative and confirmed events should look different in the dashboard widget

[graue70]

Is your feature request related to a problem? Please describe. Tentative and confirmed events look exactly the same in the dashboard widget.

Describe the solution you'd like It should be possible to visually differentiate between them.

Describe alternatives you've considered See https://github.com/nextcloud/calendar/issues/2634#issuecomment-759688990 for details.

https://github.com/nextcloud/calendar/issues/2353#issuecomment-664047134 might also be relevant.