Refactor MQ7 sensor implementation: remove old files and introduce MQ7v2 with updated reading logic

hardware/include/MQ7v2.hpp

@@ -0,0 +1,10 @@
+#include <Arduino.h>
+
+#define MQ7_PIN 34
+#define VCC 5.0
+#define ADC_RES 1023.0
+#define RL 10000.0     // 10kΩ
+#define RO 10000.0     // Resistencia del aire limpio
+
+void MQ7_Init();
+void MQ7_Read(float &sensorValue);