Restructure the native module

Consolidate all code into the src folder

native/src/include/resetprop.hpp

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <string>
+#include <functional>
+
+int setprop(const char *name, const char *value, bool prop_svc = true);
+std::string getprop(const char *name, bool persist = false);
+void getprops(void (*callback)(const char *, const char *, void *),
+        void *cookie = nullptr, bool persist = false);
+int delprop(const char *name, bool persist = false);
+void load_prop_file(const char *filename, bool prop_svc = true);