[feat] Allow CS to perform bulk actions on Stripe subscriptions from the Admin portal (#2116)

* [feat] Allow CS to perform bulk actions on Stripe subscriptions from the Admin portal

* [fix] An unrelated lint error

src/Admin/Models/StripeSubscriptionsModel.cs

@@ -0,0 +1,42 @@
+using System.ComponentModel.DataAnnotations;
+using Bit.Core.Models.BitStripe;
+
+namespace Bit.Admin.Models
+{
+    public class StripeSubscriptionRowModel
+    {
+        public Stripe.Subscription Subscription { get; set; }
+        public bool Selected { get; set; }
+
+        public StripeSubscriptionRowModel() { }
+        public StripeSubscriptionRowModel(Stripe.Subscription subscription)
+        {
+            Subscription = subscription;
+        }
+    }
+
+    public enum StripeSubscriptionsAction
+    {
+        Search,
+        PreviousPage,
+        NextPage,
+        Export,
+        BulkCancel
+    }
+
+    public class StripeSubscriptionsModel : IValidatableObject
+    {
+        public List<StripeSubscriptionRowModel> Items { get; set; }
+        public StripeSubscriptionsAction Action { get; set; } = StripeSubscriptionsAction.Search;
+        public string Message { get; set; }
+        public List<Stripe.Price> Prices { get; set; }
+        public StripeSubscriptionListOptions Filter { get; set; } = new StripeSubscriptionListOptions();
+        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
+        {
+            if (Action == StripeSubscriptionsAction.BulkCancel && Filter.Status != "unpaid")
+            {
+                yield return new ValidationResult("Bulk cancel is currently only supported for unpaid subscriptions");
+            }
+        }
+    }
+}