Physics: Consider exposing collision information somehow

[davesmith00000]

This isn't as easy as it sounds, but there are cases where it's useful to know if a collider is touching another collider.

In a platformer, knowing / enquiring if you are standing on something or pressed against something, for example.

[davesmith00000]

Solution suggested in https://github.com/PurpleKingdomGames/indigo/issues/570

World updateWithMeta could update as normal but wrap all the colliders in meta data.