2d: support animating from ResHandle<AtlasAnimations>, not just non-asset handles

examples/2d/src/main.rs

@@ -141,6 +141,7 @@ fn setup_scene_plugin(app: &mut App) {
         ("soldier_run", 0.1, 9..=16),
     ]);
     let run_anim = animations.get_active("soldier_run");
+    let animations = resman.store_new(animations);
 
     drop(resman);