Clicking a label which is only used by MRs should lead to MR search page
What
Display MRs for a given label after clicking it from a comment. Especially if there are no matching issues.
If it is a group level lable we might also want to link to the group level search.
Why
When a label is only used for MRs it confusing to land on a page showing a blank state and 0 Open
How
This could be done by having https://gitlab.com/gitlab-org/gitlab-ce/issues?label_name=Pick+into+10.5 redirect to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests?label_name=Pick+into+10.5 if there are no issues matching that label.
We can avoid redirecting when the search was intentional, either with an additional attribute or by using a special path for this search.
We might also wish to show both issues and MRs on the same page.