Link merge requests to branches in branch view

I think it would be nice to have a link to any open MR's for a given branch, within the branch view itself. I often find it hard looking at a large list of branches to know which have open MR's and which don't.

Either, there isn't an easy way to see, so hey let's make one.

Or it's not obvious, since I can't find it 😄, lets make it clearer.

👍 the issue if you think it would be a good idea

I have mocked up a few examples of what it could look like but comment/suggest others if you like:-

Compact: Verbose: An example which hasn't been merged:

I'm wary that we don't want to bloat the view, but something simple like the compact screenshot would be nice. Then there's a question of whether it should be rendered differently depending on the MR state, i.e. open, closed, merged. Do we keep the "merged" label (i think yes).