feat: support ray-casting

[Gugustinette]

Ray-casting

Raw ray-casting that tells which components collided with the ray.

• casting a ray from Point A to Point B
• casting a ray straight from a given mouse click ?
• casting a certain amount of rays within a given angle ?

Support both Rapier and Three.js ray-casting ?

https://rapier.rs/docs/user_guides/javascript/scene_queries/#ray-casting
https://threejs.org/docs/#api/en/core/Raycaster
https://threejs.org/manual/#en/picking

Add event handlers on components

We should be able to add events on components directly as below :

const cube = new FCube()
cube.onClick(() => {
  ...
})

This will probably require to cast rays on user click, so it should be explicitly activated (off by default) with something like :

new FScene({
  autoRayCasting: true
})