[AC-1608] Send offboarding survey response to Stripe on subscription cancellation (#3734)

* Added offboarding survey response to cancellation when FF is on.

* Removed service methods to prevent unnecessary upstream registrations

* Forgot to actually remove the injected command in the services

* Rui's feedback

* Add missing summary

* Missed [FromBody]

src/Core/Billing/Queries/IGetSubscriptionQuery.cs

@@ -0,0 +1,18 @@
+using Bit.Core.Entities;
+using Bit.Core.Exceptions;
+using Stripe;
+
+namespace Bit.Core.Billing.Queries;
+
+public interface IGetSubscriptionQuery
+{
+    /// <summary>
+    /// Retrieves a Stripe <see cref="Subscription"/> using the <paramref name="subscriber"/>'s <see cref="ISubscriber.GatewaySubscriptionId"/> property.
+    /// </summary>
+    /// <param name="subscriber">The organization or user to retrieve the subscription for.</param>
+    /// <returns>A Stripe <see cref="Subscription"/>.</returns>
+    /// <exception cref="ArgumentNullException">Thrown when the <paramref name="subscriber"/> is <see langword="null"/>.</exception>
+    /// <exception cref="GatewayException">Thrown when the subscriber's <see cref="ISubscriber.GatewaySubscriptionId"/> is <see langword="null"/> or empty.</exception>
+    /// <exception cref="GatewayException">Thrown when the <see cref="Subscription"/> returned from Stripe's API is null.</exception>
+    Task<Subscription> GetSubscription(ISubscriber subscriber);
+}

src/Core/Billing/Queries/Implementations/GetSubscriptionQuery.cs

@@ -0,0 +1,36 @@
+using Bit.Core.Entities;
+using Bit.Core.Services;
+using Microsoft.Extensions.Logging;
+using Stripe;
+
+using static Bit.Core.Billing.Utilities;
+
+namespace Bit.Core.Billing.Queries.Implementations;
+
+public class GetSubscriptionQuery(
+    ILogger<GetSubscriptionQuery> logger,
+    IStripeAdapter stripeAdapter) : IGetSubscriptionQuery
+{
+    public async Task<Subscription> GetSubscription(ISubscriber subscriber)
+    {
+        ArgumentNullException.ThrowIfNull(subscriber);
+
+        if (string.IsNullOrEmpty(subscriber.GatewaySubscriptionId))
+        {
+            logger.LogError("Cannot cancel subscription for subscriber ({ID}) with no GatewaySubscriptionId.", subscriber.Id);
+
+            throw ContactSupport();
+        }
+
+        var subscription = await stripeAdapter.SubscriptionGetAsync(subscriber.GatewaySubscriptionId);
+
+        if (subscription != null)
+        {
+            return subscription;
+        }
+
+        logger.LogError("Could not find Stripe subscription ({ID}) to cancel.", subscriber.GatewaySubscriptionId);
+
+        throw ContactSupport();
+    }
+}