refactor(editor): introduce MenuOrchestrator for menu management

- Added MenuOrchestrator class to handle menu construction and coordination, improving separation of concerns within the editor.
- Refactored EditorManager to delegate menu-related tasks to MenuOrchestrator, enhancing maintainability and clarity.
- Updated CMake configuration to include new source files for the MenuOrchestrator component.

Benefits:
- Streamlines menu management, leading to a more organized and efficient user experience.
- Enhances the overall architecture by clearly defining roles for menu handling and editor operations.

src/app/editor/editor_library.cmake

@@ -35,6 +35,7 @@ set(
   app/editor/system/command_palette.cc
   app/editor/system/editor_registry.cc
   app/editor/system/extension_manager.cc
+  app/editor/system/menu_orchestrator.cc
   app/editor/system/popup_manager.cc
   app/editor/system/project_manager.cc
   app/editor/system/proposal_drawer.cc