Registration can fail with a 400

[wwtamu]

Steps to reproduce:

1. Register via Admin Sign up
2. Follow link from email
3. Navigate away before completing the create password with confirm

Actual results:
see below

Expected results:
On return, display an alert with button to retry registration and have another single use token sent to email. This will require an endpoint to update user with a new front-end modal dialog to enter email to verify against. Additional persistent question and answer secrets added to registration form can be added to verify against as well.

[qtamu]

When trying to sign up the from displays a 400 error on labs

however when trying to refresh and sign up again I get another 400 error that says email has already been confirmed.