docs(example): DraggableBox does not follow the cursor smoothly (#3204)

This PR makes the `DraggableBox` movement more smooth and predictable
by:
1) adjusting `FixtureDef` and `MouseJointDef` parameters
2) setting the `MouseJoint` target to
`game.screenToWorld(event.deviceEndPosition)` rather than
`event.localEndPosition`

Fixes #3203

The comparison recordings are presented below:

<details closed><summary>GearJointExample</summary>

  | BEFORE | AFTER |
  |----------|----------|
| <video
src="https://github.com/flame-engine/flame/assets/30288967/8188ed18-e0aa-4c0f-a6c4-092015ba471c">
| <video
src="https://github.com/flame-engine/flame/assets/30288967/2388bf23-ab32-43a8-af88-a974687b6901">
|

</details>

<details closed><summary>PrismaticJointExample</summary>

  | BEFORE | AFTER |
  |----------|----------|
| <video
src="https://github.com/flame-engine/flame/assets/30288967/80ca56cd-7b7c-4a12-a551-37f268011bb0">
| <video
src="https://github.com/flame-engine/flame/assets/30288967/aaae0f7d-230b-47db-a1c2-cc39cace74e7">
|

</details>

<details closed><summary>PulleyJointExample</summary>

  | BEFORE | AFTER |
  |----------|----------|
| <video
src="https://github.com/flame-engine/flame/assets/30288967/1d40b0a0-57d2-444e-a324-63112548f9e3">
| <video
src="https://github.com/flame-engine/flame/assets/30288967/6deb1226-0f96-440f-ba72-14806612bd32">
|

</details>

<details closed><summary>RopeJointExample</summary>

  | BEFORE | AFTER |
  |----------|----------|
| <video
src="https://github.com/flame-engine/flame/assets/30288967/60b2ceee-4a41-4443-a2db-de5515270f18">
| <video
src="https://github.com/flame-engine/flame/assets/30288967/c06e35ff-2c59-4a02-b6bb-7611817a76c0">
|

</details>

examples/lib/stories/bridge_libraries/flame_forge2d/utils/boxes.dart

@@ -31,7 +31,12 @@ class Box extends BodyComponent {
   Body createBody() {
     final shape = PolygonShape()
       ..setAsBox(width / 2, height / 2, Vector2.zero(), 0);
-    final fixtureDef = FixtureDef(shape, friction: 0.3, density: 10);
+    final fixtureDef = FixtureDef(
+      shape,
+      friction: 0.3,
+      restitution: 0.2,
+      density: 10,
+    );
     final bodyDef = BodyDef(
       userData: this, // To be able to determine object in collision
       position: startPosition,
@@ -63,33 +68,42 @@ class DraggableBox extends Box with DragCallbacks {
   }
 
   @override
-  bool onDragUpdate(DragUpdateEvent info) {
-    final target = info.localEndPosition;
+  void onDragStart(DragStartEvent event) {
+    super.onDragStart(event);
+
+    final target = game.screenToWorld(event.devicePosition);
+
     final mouseJointDef = MouseJointDef()
-      ..maxForce = body.mass * 300
-      ..dampingRatio = 0
-      ..frequencyHz = 20
-      ..target.setFrom(body.position)
+      ..maxForce = 5000 * body.mass
+      ..dampingRatio = 0.1
+      ..frequencyHz = 50
+      ..target.setFrom(target)
       ..collideConnected = false
       ..bodyA = groundBody
       ..bodyB = body;
+    mouseJoint = MouseJoint(mouseJointDef);
+
+    world.createJoint(mouseJoint!);
+  }
+
+  @override
+  bool onDragUpdate(DragUpdateEvent event) {
+    mouseJoint?.setTarget(
+      game.screenToWorld(event.deviceEndPosition),
+    );
 
-    if (mouseJoint == null) {
-      mouseJoint = MouseJoint(mouseJointDef);
-      world.createJoint(mouseJoint!);
-    } else {
-      mouseJoint?.setTarget(target);
-    }
     return false;
   }
 
   @override
-  void onDragEnd(DragEndEvent info) {
-    super.onDragEnd(info);
+  void onDragEnd(DragEndEvent event) {
+    super.onDragEnd(event);
+
     if (mouseJoint == null) {
       return;
     }
+
     _destroyJoint = true;
-    info.continuePropagation = false;
+    event.continuePropagation = false;
   }
 }