use mediator to distribute messages via dispatch method

src/Sprocket.h

@@ -25,6 +25,8 @@ class Sprocket : public Mediator {
         // => see difference between standalone and mesh sprochet usage of scheduler
         Scheduler scheduler;
         Network network;
+    private:
+        SprocketMessage currentMessage;
     public:
         SprocketConfig config;
         std::vector<Plugin*> plugins;