Add MapPropertiesSystem for enhanced overworld map management

- Introduced MapPropertiesSystem class to manage map properties, including settings for area size, graphics, palettes, and overlays.
- Implemented UI components for drawing map properties, allowing users to customize map settings through a dedicated panel.
- Enhanced OverworldEditor to integrate map properties functionality, providing quick access to map settings via context menus and UI interactions.
- Added support for custom background colors and overlays, improving the overall customization experience for users.

src/app/editor/editor.cmake

@@ -13,6 +13,7 @@ set(
   app/editor/graphics/graphics_editor.cc
   app/editor/graphics/palette_editor.cc
   app/editor/overworld/tile16_editor.cc
+  app/editor/overworld/map_properties.cc
   app/editor/graphics/gfx_group_editor.cc
   app/editor/overworld/entity.cc
   app/editor/system/settings_editor.cc