Add base for IW5 menu parsing based on IW4 menu parser

src/ObjLoading/Game/IW5/Menu/MenuConversionZoneStateIW5.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <map>
+
+#include "AssetLoading/IZoneAssetLoaderState.h"
+#include "Game/IW5/IW5.h"
+
+namespace IW5
+{
+    class MenuConversionZoneState final : public IZoneAssetLoaderState
+    {
+        Zone* m_zone;
+        std::vector<Statement_s*> m_functions;
+        std::map<std::string, Statement_s*> m_function_by_name;
+
+        std::vector<StaticDvar*> m_static_dvars;
+        std::map<std::string, size_t> m_dvars_by_name;
+
+        std::vector<const char*> m_strings;
+        std::map<std::string, const char*> m_strings_by_value;
+
+    public:
+        std::map<std::string, std::vector<XAssetInfo<menuDef_t>*>> m_menus_by_filename;
+        ExpressionSupportingData* m_supporting_data;
+
+        MenuConversionZoneState();
+        void SetZone(Zone* zone) override;
+
+        Statement_s* FindFunction(const std::string& functionName);
+
+        Statement_s* AddFunction(const std::string& functionName, Statement_s* function);
+        size_t AddStaticDvar(const std::string& dvarName);
+        const char* AddString(const std::string& str);
+
+        void AddLoadedFile(std::string loadedFileName, std::vector<XAssetInfo<menuDef_t>*> menusOfFile);
+
+        void FinalizeSupportingData() const;
+    };
+}