[POS Service/Card Service] Reconcile request bodies for `POST /payment`

[njlie]

The shape of the POST /payment request body made by the POS service to card service and the OpenAPI spec for that request body on the card service differ, causing the request to fail.

• Update POS Service POST /payment call to the card service to use correct request body
• cardServiceClient.sendPayment should probably have another parameter to pass in the card service url to use, separate from the payment options