Provide a way to re-attach events on replay

[inxilpro]

Sometimes events don't need state at first but eventually do. This adds a simple way to "re-attach" all the events state during replay, effectively ensuring that everything with a #[StateId] attribute now is connected to that state for future queries. Imagine:

class UserRegistered extends Event
{
  public int $user_id;
  public int $name;
}

And later needing to track some sort of "legacy rules" value for future events:

class UserRegistered extends Event
{
  #[StateId(UserState::class)]
  public int $user_id;
  public int $name;

  public function apply(UserState $state)
  {
    $state->legacy_rules_apply = now()->isBefore('2024-01-01');
  }
}

With this feature, you can run replays with the --reattach flag, and old events that were fired before we updated our code with #[StateId(UserState::class)] will automatically get attached to the UserState before replay.

[inxilpro]

Discussed with Daniel. We'll change --reattach to --discover-states but otherwise looks good.

[gdespirito]

any updates on this? :)