Check the user has completed the document verification

[sgomez]

The user receives a QrCode and instructions about how to use it. The user scan the QrCode with the ReadId mobile app and verifies his identity. The IdP checks that a Session related with the user ReadySession request exists and finish the authentication process. The user returns to his SP.

Basic flow:

1. The user scan the QR code
2. The user scan his document with the ReadID mobile app
3. The user press a button in the UI to confirm he has finished the step 2.
4. The IdP checks the Session (AJAX request to IdentityVerificationController) exists and redirect the browser to other page (SingleSignOnReturnController)
5. The controller send a page with a POST form with the SAML authentication response and returns the user to his SP.

Extensions:

1. The mobile app says the QR code is not valid or already used
   1. The user must ask for a new QR code
2. The Session is not yet ready in step 3.
   1. The UI sends a error message and ask the user to check he really finished the flow and try again.
3. The user reload the SingleSignOnReturnController and the request does not exists
   1. Returns a no pending request error
4. The user reload the SingleSignOnReturnController and the his is not authenticated
   1. Returns to the authorization page

Preconditions:

1. The user already started the authentication flow

Postconditions:

1. The authentication request must be removed

Notes:

1. Because we don't use the webhook yet, we can use a button to request the verification status.