Add world.queueUpdate

[shakiba]

Currently several methods such as world.destroyBody() are locked when a simulation step is progress and can not be called.

The new function can be used to queue a callback to be called after an ongoing simulation step. For example:

world.on("pre-solve", () => {
  // handle collision
  world.queueUpdate((world) => {
    world.destroyBody(bullet);
  })
}

If a simulation step is not in progress, the callback is called immediately.

[shakiba]

This is the important part