Add built-in asset modules for Wolfenstein 3D v1.4 Shareware release

- Implement RetailSfxModule to map sound effects to numeric slots.
- Create SharewareAssetRegistry to manage assets for the Shareware version.
- Introduce SharewareEntityModule to define available enemies in Shareware.
- Add SharewareMenuPicModule to handle menu pictures with runtime offset computation.
- Implement SharewareMusicModule for music routing in Shareware.
- Define keys for entities, HUD elements, menu pictures, and music tracks.
- Create abstract modules for entity, HUD, menu picture, and music assets.
- Add registry resolver to select appropriate asset registry based on game version and data version.
- Update WolfensteinData to include new asset registry exports.
- Modify tests to utilize the new asset registry structure for Shareware and Retail versions.

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_dart/test/rendering/pushwall_renderer_test.dart

@@ -23,6 +23,8 @@ void main() {
       final engine = WolfEngine(
         data: WolfensteinData(
           version: GameVersion.shareware,
+          dataVersion: DataVersion.unknown,
+          registry: RetailAssetRegistry(),
           walls: [
             _solidSprite(1),
             _solidSprite(1),