Allow access to the subscription request context

Author: michaelstaib

src/HotChocolate/Core/src/Execution/Processing/ISubscription.cs

@@ -11,7 +11,12 @@ public interface ISubscription
     ulong Id { get; }
 
     /// <summary>
-    /// The compiled subscription operation.
+    /// Gets the compiled subscription operation.
     /// </summary>
     IOperation Operation { get; }
+
+    /// <summary>
+    /// Gets the global request state.
+    /// </summary>
+    IDictionary<string, object?> ContextData { get; }
 }

src/HotChocolate/Core/src/Execution/Processing/SubscriptionExecutor.Subscription.cs

@@ -118,6 +118,9 @@ public IAsyncEnumerable<IOperationResult> ExecuteAsync()
         /// <inheritdoc />
         public IOperation Operation => _requestContext.Operation!;
 
+        /// <inheritdoc />
+        public IDictionary<string, object?> ContextData => _requestContext.ContextData;
+
         public async ValueTask DisposeAsync()
         {
             if (!_disposed)