Signup Confirmation

## Description
When email is enabled, an email will be sent to the user's email address to confirm the signup. This will direct them to a page where the token can be extracted. The user will be confirmed and sent to the home page or denied and sent to a message.

### Testing Considerations
Enable emails in `config.php`, and use your gmail creds in `email.php`.
* [x] Ensure that user signup will send an confirmation email
* [x] Ensure the link in the email will allow user to confirm their email
* [x] Ensure that `/login/confirm_sent` displays properly
* [x] Ensure that `/login/failure` displays properly