Add enforceStoredCredentials setting for Worldpay (#1741)

* Add setting enforceStoredCredentials for Worldpay

* Update openapi/components/schemas/GatewayAccountConfig/Worldpay.yaml

* fix desc

Author: colinbird

openapi/components/schemas/GatewayAccountConfig/Worldpay.yaml

@@ -67,6 +67,17 @@ allOf:
             type: boolean
             description: Specifies whether to enable stored credentials.
             default: false
+          enforceStoredCredentials:
+            type: string
+            description: |-
+              Specifies whether to enforce stored credentials.
+              `mit-enabled` means that stored credentials are sent only on merchant initiated transactions. This is the expected usage.
+              `always-enabled` means that stored credentials are also used, if available, for customer facing transactions.
+            enum:
+              - disabled
+              - mit-enabled
+              - always-enabled
+            default: disabled
           merchantInitiatedReason:
             type: string
             description: Value to send with merchant-initiated transactions.