Starting to move data loader to its own package

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

lib/sprite_gallery.dart

@@ -1,9 +1,9 @@
 import 'package:flutter/material.dart';
-import 'package:wolf_dart/classes/matrix.dart';
+import 'package:wolf_3d_data/wolf_3d_data.dart';
 import 'package:wolf_dart/features/renderer/color_palette.dart';
 
 class SpriteGallery extends StatelessWidget {
-  final List<Matrix<int>> sprites;
+  final List<Sprite> sprites;
 
   const SpriteGallery({super.key, required this.sprites});
 
@@ -42,7 +42,7 @@ class SpriteGallery extends StatelessWidget {
 }
 
 class SingleSpritePainter extends CustomPainter {
-  final Matrix<int> sprite;
+  final Sprite sprite;
   SingleSpritePainter({required this.sprite});
 
   @override