allow ability to inject constructor arguments when registering actor classes

`actorRuntime.registerActor(SomeEntity.class);` doesn't allow you to inject constructor arguments inside `SomeEntity`. Using
`getDeclaredConstructor().newInstance()` or similar approach we should be able to allow constructor arguments whilst registering actor classes.

Start at actorRuntime.registerActor(SomeEntity.class) and trace the actor registration and reflection-based construction path. Determine how constructor arguments should be supplied and managed during actor creation, then verify that a registered SomeEntity can be instantiated with those arguments and that existing no-argument registration remains supported.

Scritto dal modello di indicizzazione a partire dal testo della issue.