Allow setting max outstanding publisher confirms

Part of #1682

Author: lukebakken

projects/RabbitMQ.Client/Impl/Channel.BasicPublish.cs

@@ -32,6 +32,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using RabbitMQ.Client.Framing;
@@ -220,5 +221,16 @@ void MaybeAddPublishSequenceNumberToHeaders(IDictionary<string, object?> headers
                 }
             }
         }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private ValueTask EnforceFlowControlAsync(CancellationToken cancellationToken)
+        {
+            if (_flowControlBlock.IsSet)
+            {
+                return default;
+            }
+
+            return _flowControlBlock.WaitAsync(cancellationToken);
+        }
     }
 }

projects/RabbitMQ.Client/Impl/Channel.cs

@@ -450,17 +450,6 @@ protected ValueTask ModelSendAsync<TMethod, THeader>(in TMethod method, in THead
             return Session.TransmitAsync(in method, in header, body, cancellationToken);
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        protected ValueTask EnforceFlowControlAsync(CancellationToken cancellationToken)
-        {
-            if (_flowControlBlock.IsSet)
-            {
-                return default;
-            }
-
-            return _flowControlBlock.WaitAsync(cancellationToken);
-        }
-
         internal Task OnCallbackExceptionAsync(CallbackExceptionEventArgs args)
         {
             return _callbackExceptionAsyncWrapper.InvokeAsync(this, args);