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

src/Config.h

@@ -1,6 +1,27 @@
 #pragma once
 #include <Figments.h>
 #include "JsonCoordinateMapping.h"
+#include <ArduinoJson.h>
+
+class Configuration {
+  public:
+    Configuration(const JsonObject& data);
+    const char* get(const char* key, const char* defaultVal) const;
+    int get(const char* key, int defaultVal) const;
+    bool get(const char* key, bool defaultVal) const;
+
+  private:
+    const JsonObject& m_json;
+};
+
+class ConfigTaskMixin : public virtual Loopable {
+  public:
+    void handleEvent(const InputEvent &evt) override;
+
+    void loop() override {}
+
+    virtual void handleConfigChange(const Configuration& config) {}
+};
 
 struct HardwareConfig {
     uint8_t version = 3;