Reorganize solution structure.

Source/MQTTnet.AspnetCore/MqttWebSocketServerAdapter.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Net.WebSockets;
+using System.Threading.Tasks;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Implementations;
+using MQTTnet.Serializer;
+using MQTTnet.Server;
+
+namespace MQTTnet.AspNetCore
+{
+    public class MqttWebSocketServerAdapter : IMqttServerAdapter
+    {
+        public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
+
+        public Task StartAsync(IMqttServerOptions options)
+        {
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync()
+        {
+            return Task.CompletedTask;
+        }
+
+        public async Task RunWebSocketConnectionAsync(WebSocket webSocket, string endpoint)
+        {
+            if (webSocket == null) throw new ArgumentNullException(nameof(webSocket));
+
+            var clientAdapter = new MqttChannelAdapter(new MqttWebSocketChannel(webSocket, endpoint), new MqttPacketSerializer(), new MqttNetLogger().CreateChildLogger(nameof(MqttWebSocketServerAdapter)));
+
+            var eventArgs = new MqttServerAdapterClientAcceptedEventArgs(clientAdapter);
+            ClientAccepted?.Invoke(this, eventArgs);
+
+            if (eventArgs.SessionTask != null)
+            {
+                await eventArgs.SessionTask.ConfigureAwait(false);
+            }
+        }
+        
+        public void Dispose()
+        {
+            StopAsync().GetAwaiter().GetResult();
+        }
+    }
+}