front: display block states on the map in the simulation results

[Khoyo]

Who would benefit from this feature?

End users

What is this feature about?

#3473 dropped the display of route_occupancies on the map, since routes don't correspond to blocks anymore.

Why is this feature valuable?

We need to bring back a display of block states in a correct way regarding the new, more accurate signaling model.

Anything else people should know?

Projections have to be taken into account. The blocks that are simulated may not follow the path of the train if it differs from the current projection path. Or the backend could simulated and return both set of states.