Add diagnosis module via HTTP.

include/diagnosis.h

@@ -0,0 +1,26 @@
+#ifndef DIAGNOSIS_H
+#define DIAGNOSIS_H
+
+#include <Arduino.h>
+#include "led_matrix.h"
+#include "udp_logger.h"
+
+class Diagnosis
+{
+public:
+    Diagnosis();                                     // constructor
+    Diagnosis(UDPLogger *logger, LEDMatrix *matrix); // constructor
+
+    String handle_command(const String &command);
+    String print_device_info();
+    String print_sketch_info();
+    String print_last_reset_details();
+    String print_matrix_fps();
+
+private:
+    UDPLogger *_logger;
+    LEDMatrix * _matrix;
+    void print(const String &s);
+};
+
+#endif // DIAGNOSIS_H