Add "Curator" identifier after usernames in observers and identifiers lists

[cthawley]

I like the idea behind this suggestion - there needs to be a better way to surface curators working in specific groups with the new 5 curator requirement for some changes.

But I also agree that

@upupa-epops

I like the way in which staff, curators, and everyone else are portrayed the same way in leaderboards and elsewhere; it’s consistent with the implicit philosophy across the platform that all of our observations and identifications can theoretically be of equal value.

Maybe there’s a way to only show curators on leaderboards to other curators for this purpose? Or something different to make it easier to surface curators who are familiar with some groups?