Make re-sending the email confirmation possible for registrations

One-sentence description

Make re-sending the email confirmation possible for registrations

Desired behaviour

Have a button to resend the email confirmation (in the admin), since it's possible that someone might not receive it. Correcting the email address in the admin should be possibly too, if someone made a typo. This way we can correct the values without having to delete the whole registration and let new members do it all over.