Refactoring, housekeeping, documentation

Add a class diagram. Still needs some details.
Refactor to better respect SOLID principles.
Housekeeping, move and rename classes/files.

app/include/sensor/GPUSensorsFacade.h

@@ -0,0 +1,14 @@
+#ifndef GPUSENSORSFACADE_H_
+#define GPUSENSORSFACADE_H_
+
+#include <memory>
+#include <vector>
+
+#include <sensor/Sensor.h>
+
+class GPUSensorsFacade {
+public:
+  std::vector<std::shared_ptr<Sensor>> TemperatureSensors();
+};
+
+#endif // GPUSENSORSFACADE_H_