Work request tabs (#809)

Not feature complete, but I think that a review (and merge) would be good to avoid a huge review.

The current implementation should have the same information as before. It needs some more reshuffling as per #809 (closed) and adding some new information (also #809 (closed)).

The sidebar should be gone in a similar way as #794 (closed) (I will work on that one again as well).

I've attached screenshots. if a playground is preferred I can generate it (I suspect that I will need to create some work requests with enough data for that).