Device flows verification_uri

The device flow requires the client be presented with a verification_uri.

The verification_uri value needs to be changed per deployment because the exact details of the point of contact are not known by the authorization server and the response is written back in JSON not HTML. In order to update the verification_uri shown in the response from device_authorize, use the Post Token mapping rule and update the variable webseal_portion to be the new protocol, hostname, port, and junction to user in the URI.