wip: move gfx to gfxhook, some borderless window stuff

gfxhook/config.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stddef.h>
+
+#include "gfxhook/gfx.h"
+
+void gfx_config_load(struct gfx_config *cfg, const wchar_t *filename);