ADD: added methode for message handling in the directCommsClient and Server

include/DirectCommunicationClient.hpp

@@ -7,6 +7,7 @@
 #include "zmq.hpp"
 #include <atomic>
 #include <cstdint>
+#include <functional>
 #include <memory>
 #include <string>
 #include <sys/types.h>
@@ -27,6 +28,9 @@ namespace DirectCommunication
             void sendMessage(std::string msg);
             std::string getLatestMessage();
 
+            void registerMessageCallback(std::function<void(std::string)> MessageHandle);
+
+
         private:
             ushort port_;
             std::string serverAddress_;
@@ -40,6 +44,8 @@ namespace DirectCommunication
 
             std::atomic_bool isConnected = true;
 
+            std::function<void(std::string)> MessageHandle_ = nullptr;
+
 
             WHISPER::threadSafeQueue<std::string> receivedMessages_;