Merge Request Security Widget for GitLab per Robin Kehl

A browser extension that summarizes the security report artifacts your merge request pipeline already produces, on instances where those reports are otherwise reachable only as raw JSON downloads.

It finds the security report artifacts attached to the merge request's head pipeline, downloads them with your existing GitLab session, and renders a summary above the merge widget. It then reads the target branch's own reports the same way, so the findings this merge request introduces are told apart from the ones the branch already had.