Creates a ActorMaterializer which will execute every step of a transformation pipeline within its own ActorBase. The required IActorRefFactory (which can be either an ActorSystem or an IActorContext) will be used to create one actor that in turn creates actors for the transformation steps.

The materializer's ActorMaterializerSettings will be obtained from the configuration of the context's underlying ActorSystem.

The namePrefix is used as the first part of the names of the actors running the processing steps. The default namePrefix is "flow". The actor names are built up of namePrefix-flowNumber-flowStepNumber-stepName.