Port ActorSystemSetup

[Aaronontheweb]

Version: 1.4.6 and later

This feature exists on the JVM primarily to support compile-time dependency injection of serializers and other configuration elements. I think we can use it in Akka.NET to do the same, but also to potentially resolve some issues such as #1675

I think we can use ActorSystemSetup to do the following:

1. Same as JVM - pass in Config elements programmatically before the ActorSystem starts
2. Use Action type builders to configure parts of the ActorSystem prior to creating any actors - this could be used to do things like safely instantiate the a DI kernel or to instrument specific ActorSystemExtensions.