Merge request lists reorganization
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### Proposal
There is a lot of information on the merge request item in a list

There is an opportunity to refine the information.
### Possible changes
- Table/grid alignment for better scanability https://gitlab.com/gitlab-org/gitlab/-/merge_requests/149024#note_1857450675
- Could "assignee" replace "created by" in the list view
- Smarter states reviewer avatars to show which reviewer requires approval
- On thelist we show threads as `7/10 resolved` however on the MR page we show that information as `3 open threads`
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