Changes to List all adyen gateways

added the optional property data/items/attributes/token_webhook_endpoint_secret to the response with the 200 status

added the optional property data/items/attributes/webhook_endpoint_id to the response with the 200 status

added the optional property data/items/attributes/idempotency_window_mins to the response with the 200 status

added the media type application/vnd.api+json for the response with the status 200