Add required attributes that should always be present in every (valid) voucher definition

src/openapi/products/SE-vouchers-supplier.yaml

@@ -728,6 +728,14 @@ components:
             $ref: "#/components/schemas/supplierTouchpointVoucherDefinitionResponse"
     supplierTouchpointVoucherDefinitionResponse:
       type: object
+      required:
+        - productId
+        - productName
+        - productDescription
+        - validityPeriod
+        - productCategory
+        - sellingPeriods
+        
       properties:
         productId:
           type: integer