Add "Confirm user" button to admin page
What does this MR do?
This MR adds a "Confirm user" to the admin user page.
Why was this MR needed?
There is no way for an admin to force a user confirmation. Some users create users in the API and then don't have a way to force the user into a confirmed state.
Originally, I attempted to add a link to allow the admin to resend a confirmation e-mail. But that may not be helpful because a user can be in the unconfirmed state with no unconfirmed_email set.
Screenshot
