De-coupled remaining aspects of game into packages

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

packages/wolf_3d_flutter/lib/audio/audio_adaptor.dart

@@ -0,0 +1,15 @@
+import 'package:wolf_3d_data_types/wolf_3d_data_types.dart';
+import 'package:wolf_3d_engine/wolf_3d_engine.dart';
+import 'package:wolf_3d_flutter/wolf_3d.dart';
+
+class FlutterAudioAdapter implements EngineAudio {
+  @override
+  void playLevelMusic(WolfLevel level) {
+    Wolf3d.I.audio.playLevelMusic(level);
+  }
+
+  @override
+  void stopMusic() {
+    Wolf3d.I.audio.stopMusic();
+  }
+}