Add Redundancy to PowerPlant Simulator

[joesan]

Right now only one instance of the simulator can be run. As we build StateMachines using Akka only one instance can be runnable. We need to however make the StateMachines redundant, meaning that we have to be able to spin up another instance on demand or when the application that runs the PowerPlant goes down.

This can be done using Akka Persistence and Akka Cluster Sharding. Refer to the following documentation:

https://doc.akka.io/docs/akka/current/cluster-sharding.html

https://doc.akka.io/docs/akka/current/persistence.html