Port Event Simulator from Kompics

[Bathtor]

While it may be very difficult to provide the determinism guarantees Kompics' Simulator has in Rust, at least porting the network models and the simulation event scheduler, together with some DSL for describing scenarios is probably quite reasonable.

In fact the hash wheel timers crate we use already comes with an empty-slot-skipping simulation timer for exactly this purpose.

Note that this should probably be a separate crate, but we'll track it here for now until such a crate is created.