train reliability improvements

[Novakasa]

Instead of just sending the next expected marker and the behavior, send the full list of markers until the next block, with markers tagged if they have a role in the block, and also send the expected behaviour (stop in block / pass the block)

That way, if something changes (can't pass anymore) we just have to send the new behavior and the train itself knows whether it should have slowed down by now and correct for it.

All other solutions are unreliable since we don't know for sure if the train already passed a specific marker or not.

[Novakasa]

also, anytime a train starts a route leg (locks some tracks) other trains should re-check immediately whether they can still pass their next block.

[Novakasa]

when the train passes, we could already send the instructions for the next leg, which should be buffered by the train (it still needs to finish the previous instructions).

[Novakasa]

we could simulate the reliability without real trains by adding a communication delay to VirtualTrain

[Novakasa]

this has been mostly implemented since f0a8b3d and previous commits