UI: Add red circle to the FAQ tab when something new is posted

[JanaNF]

Is your feature request related to a problem?

I'm frustrated that nobody checks the FAQ for new posts. However, I have noticed that we don't show in Artemis that there is a new post. The same can be said for the other tabs like "Lecture" or "Exercises". It would be great if we could at least add the red circle like we do it for "Communication" when there is a new post.

Describe the solution you'd like

When there is a new FAQ post, there should be a red circle to notify the user that a new post was added.
You could also consider implementing the same for the other tabs.

Describe alternatives you've considered

No response

Additional context

No response