Add mocked broker client

Hcs.WebApp/Services/IClientProvider.cs

@@ -0,0 +1,11 @@
+using Hcs.Broker;
+using Hcs.Broker.MessageCapturer;
+using Hcs.WebApp.Config;
+
+namespace Hcs.WebApp.Services
+{
+    public interface IClientProvider
+    {
+        IClient CreateClient(BrokerConfig config, Broker.Logger.ILogger logger, IMessageCapturer messageCapturer);
+    }
+}