[AC-1423] Add AddonProduct and BitwardenProduct properties to BillingSubscriptionItem (#3037)

* [AC-1423] Add AddonProduct and BitwardenProduct properties to BillingSubscriptionItem

- Add a helper method to determine the appropriate addon type based on the subscription items StripeId

* [AC-1423] Add helper to StaticStore.cs to find a Plan by StripePlanId

* [AC-1423] Use the helper method to set SubscriptionInfo.BitwardenProduct

src/Api/Models/Response/SubscriptionResponseModel.cs

@@ -1,4 +1,5 @@
 using Bit.Core.Entities;
+using Bit.Core.Enums;
 using Bit.Core.Models.Api;
 using Bit.Core.Models.Business;
 using Bit.Core.Utilities;
@@ -82,6 +83,8 @@ public class BillingSubscription
             Interval = item.Interval;
             Quantity = item.Quantity;
             SponsoredSubscriptionItem = item.SponsoredSubscriptionItem;
+            AddonSubscriptionItem = item.AddonSubscriptionItem;
+            BitwardenProduct = item.BitwardenProduct;
         }
 
         public string Name { get; set; }
@@ -89,6 +92,8 @@ public class BillingSubscription
         public int Quantity { get; set; }
         public string Interval { get; set; }
         public bool SponsoredSubscriptionItem { get; set; }
+        public bool AddonSubscriptionItem { get; set; }
+        public BitwardenProductType BitwardenProduct { get; set; }
     }
 }