Reactive Steps #477
Description
Everything is a step in Motia, but different types of steps are basically different triggers and
different expected input types. We want to allow developers to configure specific triggers to their
steps.
- Subscribing to a State change, trigger would be whenever a state field is updated.
- Subscribing to a Stream, trigger would be whenever a new message is added to the stream.
- Conditional triggers: Pretty much the same we have, but with some conditions to be checked before the step is executed.