Explanation if SCA authentication required when adding Stripe payment for an order in the admin section

[kristinalim]

Description

• Relates to Support for Strong Customer Authentication (SCA) in Stripe integration - Part 2 #4170

- As a: enterprise user
- On page: /admin/orders/ORDER_NUMBER/payments
- I want to be able to: know when SCA authentication required if SCA authentication is required for the card being used.

Acceptance Criteria

As enterprise user:

1. Go to the "New Payment" form for an order that allows Stripe payment method.
2. Use a card that needs SCA authentication. See Stripe regulatory test cards here.
3. I should be able to see error explaining that SCA authentication is required.