Please add guardian-supervisor-strategy tot he Fluent API

[stevemesser]

We are trying to update our application to use the Fluent API for configuration and after asking about this Aaron suggested creating an issue for it.

We would to be able to configure the following via the Fluent API:

akka
{
actor
{
guardian-supervisor-strategy = "BatchProcessorLibrary.Akka.GuardianSupervisorStrategy, BatchProcessorLibrary"
}
}

[Danthar]

This issue also needs or could use integration in the fluent api. And is of a similar vein as the guardian strategy setting.

akkadotnet/akka.net#7595

Ill start a PR to work on this in the coming time.