Ability to sort admin users list, repos list, etc. by different columns

Created by: dadlerj

Requested by https://app.hubspot.com/contacts/2762526/company/693777200

They'd like to sort the user list by how recently users have been active. I've tried to add this in the past, but it's difficult to do this with our filteredconnection structure.

And of course, even if filteredconnections supported it, it's hard to do this in general given each table is generated in its own way on the backend, and we may not have a GraphQL resolver that accepts an order option...

If helpful, we can break this out into issues for each list.