Network simulator

[MohammedAljahdali]

I added a simple network latency simulator feature to the simulation.

The feature can be used by providing an optional kwarg dictionary:

start_simulation(
        ...,
        network_simulator_kwargs={"avg_latency_ms": 550, "latency_variance_ms": 50,
                                  "avg_bandwidth_mbps": 100, "bandwidth_variance_mbps": 10},
    )

By default network_simulator_kwargs = None and the simulator is not used, and will only be used if the network_simulator_kwargs is provided.