[core] Add emit support for all actor logic creators

[davidkpiano]

This PR adds support for emitting events from all actor logic types:

Promise actors

const logic = fromPromise(async ({ emit }) => {
  // ...
  emit({
    type: 'emitted',
    msg: 'hello'
  });
  // ...
});

Transition actors

const logic = fromTransition((state, event, { emit }) => {
  // ...
  emit({
    type: 'emitted',
    msg: 'hello'
  });
  // ...
  return state;
}, {});

Observable actors

const logic = fromObservable(({ emit }) => {
  // ...

  emit({
    type: 'emitted',
    msg: 'hello'
  });

  // ...
});

Callback actors

const logic = fromCallback(({ emit }) => {
  // ...
  emit({
    type: 'emitted',
    msg: 'hello'
  });
  // ...
});

[changeset-bot]

🦋 Changeset detected

Latest commit: 43716f6

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
xstate	Minor

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