Credit card verification after sign up

Ref: https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/82

What does this MR do and why?

This MR implements credit card verification flow that will be part of a larger "Identity Verification flow" (credit card, phone number, and email verification).

It reuses the ZuoraSimple Vue component that displays a credit card form used for verification.

Screenshots or screen recordings

Screen_Recording_2022-09-06_at_4.04.00_PM

How to set up and validate locally

1. Ensure that you have a running CustomersDot installation locally and Zuora is set up to use GL.com CC Validation_registration hosted page with the correct callback to your local GDK instance
2. Enable feature flag

   $ rails console
   > Feature.enable(:identity_verification)

3. Sign in and navigate to http://localhost:3000/users/identity_verification
4. Validate that credit card form is displayed
   Screenshot

   
5. Fill up and submit the form with the following values

   Name on card: Any name
   Card number: 4242 4242 4242 4242
   Expiration date: Any future date
   CVC: Any 3-digit number

6. Validate that the submit button is disabled while the form is being submitted
7. Validate that the form is hidden when processing completes

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.