Semi-working refactor of merch for multiple shelves

Code is now capable of loading merch onto multiple store shelves during load shop.

Still need to fix refresh, loading merch after creating merch and making transactions, the shelf buttons, as well as saving the state of the shelves to the server.

src/utils.h

@@ -1,3 +1,4 @@
 #pragma once
 RE::NiMatrix3 get_rotation_matrix(RE::NiPoint3 rotation);
 RE::NiPoint3 rotate_point(RE::NiPoint3 point, RE::NiMatrix3 rotation_matrix);
+std::pair<uint32_t, const char*> get_local_form_id_and_mod_name(RE::TESForm* form);