Resend verification message when unverified user attempts to authenticate.

[#79720994] https://www.pivotaltracker.com/story/show/79720994

Signed-off-by: Madhura Bhave <mbhave@gopivotal.com>
Remove unreachable test code

Signed-off-by: Madhura Bhave <mbhave@gopivotal.com>
Include client Id when re-generating verification code
 - Use new AuthenticationDetailsSource to get saved request (has the client_id).

[#79720994] https://www.pivotaltracker.com/story/show/79720994

Signed-off-by: Madhura Bhave <mbhave@gopivotal.com>
Signed-off-by: Rob Szumlakowski <rszumlakowski@pivotal.io>
Signed-off-by: Madhura Bhave <mbhave@gopivotal.com>