feat: Adding paint attribute to SpriteWidget and SpriteAnimationWidget (#3298)

Adds a `Paint` attribute to the `SpriteWidget` and
`SpriteAnimationWidget` for an improved API.

---------

Co-authored-by: Lukas Klingsbo <me@lukas.fyi>

examples/lib/stories/widgets/sprite_widget_example.dart

@@ -1,6 +1,7 @@
 import 'dart:math';
 
 import 'package:dashbook/dashbook.dart';
+import 'package:examples/stories/widgets/paints.dart';
 import 'package:flame/widgets.dart';
 import 'package:flutter/material.dart';
 
@@ -17,6 +18,13 @@ Widget spriteWidgetBuilder(DashbookContext ctx) {
       anchor: Anchor.valueOf(
         ctx.listProperty('anchor', 'center', anchorOptions),
       ),
+      paint: paintList[paintChoices.indexOf(
+        ctx.listProperty(
+          'paint',
+          'none',
+          paintChoices,
+        ),
+      )],
     ),
   );
 }