refactor(editor): extract editor management responsibilities into dedicated classes

- Introduced EditorRegistry, ProjectManager, and RomFileManager to streamline editor operations and improve code organization.
- Refactored EditorManager to delegate responsibilities to the new classes, enhancing maintainability and clarity.
- Updated CMake configuration to include new source files for the extracted components.

Benefits:
- Improves separation of concerns within the editor, leading to a more modular and manageable codebase.
- Enhances the overall architecture by clearly defining roles for editor management, project handling, and ROM file operations.

src/app/editor/system/window_delegate.h

@@ -53,6 +53,11 @@ class WindowDelegate {
   absl::Status ResetLayout();
   std::vector<std::string> GetAvailableLayouts() const;
   
+  // Workspace-specific layout methods (match EditorManager API)
+  void SaveWorkspaceLayout();
+  void LoadWorkspaceLayout();
+  void ResetWorkspaceLayout();
+  
   // Window state queries
   std::vector<std::string> GetVisibleWindows() const;
   std::vector<std::string> GetHiddenWindows() const;