Draft: refactor and improve lane assignment and road assignment

In the old architecture, the lane assignment and road alignment services would run at each step of the simulation

This change introduces callbacks on entity creation and position change to reduce useless computations, in particular for static objects

In addition, we now align static objects to the road surface, if the user setting is set; we use the mount height attribute to know the actual desired offset from the road surface

Finally, we also allow for a lateral tolerance to be set and taken into account when projecting to an entity