Character limit on usernames

[trouille]

In our #moderation-reports slack channel, the question of imposing character limits on usernames came up because of: https://www.zooniverse.org/users/theequatorelevatorelevatesasnackeraidereatenbyagaterb[…]nbyapuffinthanthepuffinstartedcussincuzthemuffinwassobussin

This may be a front-end question, but I thought first to post in Panoptes.

First would be to check what's the spread in character counts for usernames, see what's the tail end, and put a very lenient character limit in place, if we do choose to do that.

This hasn't come up many times (at least on my radar), so I don't think it's a pervasive issue. But good to document, raise the question, see if there's a simple solution and something we want to implement.