Group labels with the same colon prefix together
In https://gitlab.com/gitlab-org/gitlab-ee/issues/5805#note_130920800 and below, we added scoped labels. These are labels like ~"Category::Accessibility Testing", where you can only add one ~Category label to an issue, MR, or epic at once: adding a new one replaces the old one.
I think it would also be interesting to allow a variant of these that have multiple values using a single colon. For instance, browser:chrome and browser:edge.
This is already how labels work! But we could improve the UI by taking something like this mockup from https://gitlab.com/gitlab-org/gitlab-ee/issues/5805#note_117704577, and adapting it to match the existing prefixes:
(Imagine that wasn't drawn in crayon.)
I think we had another issue for this somewhere but I can't find it right now. @annabeldunstone @ebrinkman what do you think?