config: add new Configuration class to simplify handling json config update api

src/platform/arduino/MQTTTelemetry.h

@@ -3,6 +3,7 @@
 
 #include <PubSubClient.h>
 #include <ArduinoLog.h>
+#include "../../Config.h"
 
 #include "../../Sequencer.h"
 
@@ -47,7 +48,7 @@ class MQTTTelemetry : public BufferedInputSource, OnlineTaskMixin, ConfigTaskMix
 
     void handleEvent(const InputEvent& evt) override;
     void handleEventOnline(const InputEvent& evt) override;
-    void handleConfigChange(const InputEvent& evt) override;
+    void handleConfigChange(const Configuration& cfg) override;
     void loop() override;
 
     void loopOnline() override;