Refactor naming for background tasks.

Source/MQTTnet/Server/MqttClientConnection.cs

@@ -160,7 +160,7 @@ namespace MQTTnet.Server
 
                 await SendAsync(_channelAdapter.PacketFormatterAdapter.DataConverter.CreateConnAckPacket(_connectionValidatorContext), cancellationToken).ConfigureAwait(false);
 
-                Task.Run(() => SendPendingPacketsAsync(cancellationToken), cancellationToken).Forget(_logger);
+                Task.Run(() => SendPendingPacketsAsync(cancellationToken), cancellationToken).RunInBackground(_logger);
 
                 Session.IsCleanSession = false;
 

Source/MQTTnet/Server/MqttClientSessionsManager.cs

@@ -50,7 +50,7 @@ namespace MQTTnet.Server
 
         public void Start(CancellationToken cancellationToken)
         {
-            Task.Run(() => TryProcessQueuedApplicationMessagesAsync(cancellationToken), cancellationToken).Forget(_logger);
+            Task.Run(() => TryProcessQueuedApplicationMessagesAsync(cancellationToken), cancellationToken).RunInBackground(_logger);
         }
 
         public async Task HandleClientConnectionAsync(IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)

Source/MQTTnet/Server/MqttServerKeepAliveMonitor.cs

@@ -29,7 +29,7 @@ namespace MQTTnet.Server
             // support async/await. Async etc. is avoided here because the thread will usually check
             // the connections every few milliseconds and thus the context changes (due to async) are 
             // only consuming resources. Also there is just 1 thread for the entire server which is fine at all!
-            Task.Factory.StartNew(_ => DoWork(cancellationToken), cancellationToken, TaskCreationOptions.LongRunning).Forget(_logger);
+            Task.Factory.StartNew(_ => DoWork(cancellationToken), cancellationToken, TaskCreationOptions.LongRunning).RunInBackground(_logger);
         }
 
         void DoWork(CancellationToken cancellationToken)