refactor: Update window creation and file dialog handling for improved consistency

- Replaced `SDL_Deleter` with `util::SDL_Deleter` in window creation for better utility usage.
- Updated file dialog methods to consistently reference `core::FeatureFlags` for feature flag checks.
- Refactored file extension retrieval in `EditorManager` to use `util::GetFileExtension` for consistency.
- Adjusted `MusicEditor` constructor to accept a ROM pointer, enhancing initialization clarity.
- Commented out unused code in `MusicEditor` to improve readability and maintainability.
- Updated include paths in `overworld_editor.cc` for better organization.
- Cleaned up commented-out code in `editor_selection_dialog.cc` and `welcome_screen.cc` for clarity.

src/cli/handlers/project.cc

@@ -1,6 +1,6 @@
 #include "app/core/project.h"
 #include "cli/z3ed.h"
-#include "core/platform/file_dialog.h"
+#include "util/file_util.h"
 #include "util/bps.h"
 #ifndef _WIN32
 #include <glob.h>