Can we make parent to child startup state passing less implicit

[goodboy]

As per my comment in #133, it would be good to have a more explicit setting/transfer of state to a child process on startup besides this setattr loop.

A couple things I can think of offhand include:

• tryin attrs style instance variables
• consider storing all the data in a single instance variable that can be easily serialized for debugging (like a dataclass)
• don't actually store it on the Actor but instead in a global _state.py variable?