Add support for collision contact points and normals

[kevzettler]

This Pr updates the physics pipeline to expose collision contact points and normals. Still testing this but opening it up for review and discussion.

[kevzettler]

Ok looking legit on the points data

contactvid.mp4

Ok some testing. rendering a yellow sphere anywhere one of the collision points like

    Collision::subscribe(move |msg| {
        for position in &msg.points {
            Sphere {
                ..Sphere::suggested()
            }
            .make()
            .with_merge(
                Transformable {
                    optional: TransformableOptional {
                        translation: Some(*position),
                        scale: Some(Vec3::ONE),
                        rotation: Some(Quat::IDENTITY),
                    },
                    ..Transformable::suggested()
                }
                .make(),
            )
            .with(name(), "DebugMarker".to_string())
            .with(self::color(), vec4(1., 0.7, 0., 1.0))
            .spawn();
        }
        }
     ```

[FredrikNoren]

Awesome! This looks great to me; @philpax any thoughts?