Current Behaviour

When trying to update the billing address in the Stripe edit details form on the Developer Portal it can fail due to THREESCALE-9532 and the user does not know that it failed or why leading to a poor experience.

Errors are not returned to the logged in user when either of the following are true:

1. Billing address is being updated but card details are not and so the update will fail as detailed in the issue description.
EDIT (Joan). IT will not fail, it's fixed: https://github.com/3scale/porta/pull/3696

2. Billing address and/or card details are being updated but the card details are invalid and so the update will fail for an unknown reason to the user.

In both the above cases if the currently saved or newly entered card details are invalid for any reason that would normally generate an error that error is not returned to the user, in fact, no error is returned which makes it impossible for the user to know that there is even an issue with the card and this can cause a loss of finances for the API Provider as a result.

Expected Behaviour

When attempting to update the billing address in the Stripe edit details form on the Developer Portal any failed attempts should render a flash error message with the appropriate response error (depending on what the Stripe API returns).