As described in Step 3 of https://docs.adyen.com/online-payments/drop-in-web
May require adding an API call in SmashPig and plumbing it through the AdyenAdapter
Full parameters of the Adyen API call we need to make are available at
https://docs.adyen.com/api-explorer/#/CheckoutService/v67/post/payments
For this step, let's just make it handle credit card submissions.