Reorganized UnityEngine namespace

Reorganized UnityEngine namespace by splitting headers into individual classes

lib/private/UnityEngine/Input.cpp

@@ -0,0 +1,9 @@
+#include "pch-il2cpp.h"
+
+#include "UnityEngine/Input.h"
+#include <helpers.h>
+
+float Input::GetAxis(const char* axisName)
+{
+	return app::Input_1_GetAxis(ConvertToSystemString(axisName), nullptr);
+}