Move managed client to separate nuget.

Extensions/MQTTnet.Extensions.ManagedClient/IManagedMqttClient.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public interface IManagedMqttClient : IApplicationMessageReceiver, IApplicationMessagePublisher, IDisposable
+    {
+        bool IsStarted { get; }
+        bool IsConnected { get; }
+
+        event EventHandler<MqttClientConnectedEventArgs> Connected;
+        event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
+
+        event EventHandler<ApplicationMessageProcessedEventArgs> ApplicationMessageProcessed;
+
+        Task StartAsync(IManagedMqttClientOptions options);
+        Task StopAsync();
+
+        Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters);
+        Task UnsubscribeAsync(IEnumerable<string> topics);
+    }
+}