PROMO-1050 Add shipping discount action

PROMO-1050 Add as_total field to shipping discount action

PROMO-1050 Remove as_total field from shipping discount action

PROMO-1050 Restrict count of shipping method IDs to 250

PROMO-1050 Add ShippingDiscountAction as valid action

Author: bc-luke

reference/promotions.v3.yml

@@ -1076,6 +1076,35 @@ components:
                     minimum: 1
           required:
             - zone_ids
+    ShippingDiscountAction:
+      title: Shipping Discount Action
+      type: object
+      description: |-
+        **Shipping Discount Action**
+        Discounts shipping, optionally restricted to specific shipping methods.
+      properties:
+        shipping_discount:
+          type: object
+          properties:
+            discount:
+              $ref: '#/components/schemas/Discount'
+            method_ids:
+              description: ''
+              oneOf:
+                - type: string
+                  enum:
+                    - '*'
+                  description: All configured shipping methods.
+                - type: array
+                  uniqueItems: true
+                  description: List of shipping method IDs to which the shipping discount can apply.
+                  items:
+                    type: integer
+                    minimum: 1
+                    maximum: 250
+          required:
+            - method_ids
+            - discount
     Discount:
       title: Discount
       description: '**Discount**'
@@ -1346,6 +1375,7 @@ components:
         - $ref: '#/components/schemas/GiftItemAction'
         - $ref: '#/components/schemas/FixedPriceSetAction'
         - $ref: '#/components/schemas/ShippingAction'
+        - $ref: '#/components/schemas/ShippingDiscountAction'
     ProductOptionsItemMatcher:
       title: Product Options Item Matcher
       type: object