Show related merge request in branches list and branch single view

When I have dozens of branches and only some of them are being handled in open (or closed?) merge requests, it is difficult to get an overview of which branches still have no merge request. You can even start a new merge request if you are not aware of an already open one.

So my suggestion is:

• In the "Branches" view switch the "+ Merge Request" button into "Open Merge Request" linking to a merge request that uses this branch.
• In the single "Branch" view, do the same for this particular branch.

In the "Compare" view there is already this feature! If I use the "+ Merge Request" button while there is already an open one, after filling the details and saving, I end up with the error "Validate branches Cannot Create: This merge request already exists: ["xxx"]". A bit frustrating. :)

Maybe this issue has been reported already, but I tried hard to find it using the issue search (and google) and could not find anything about it yet.