feat(store): add createActionGroup function

[markostanimirovic]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/ngrx/platform/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Documentation has been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Closes #3337

What is the new behavior?

const authApiActions = createActionGroup({
  source: 'Auth API',
  events: {
    'Login Success': props<{ userId: number; token: string }>(),
    'Login Failure': props<{ error: string }>(),
    'Logout Success': emptyProps(),
    'Logout Failure': (error: Error) => ({ error }),
  },
});

authApiActions.loginSuccess({ userId: 10, token: 'ngrx' });
authApiActions.loginFailure({ error: 'Login Failure!' });
authApiActions.logoutSuccess();
authApiActions.logoutFailure(new Error('Logout Failure!'));

Does this PR introduce a breaking change?

[ ] Yes
[x] No

[netlify]

✅ Deploy Preview for ngrx-io canceled.

Built without sensitive environment variables

Name	Link
🔨 Latest commit	d885389
🔍 Latest deploy log	https://app.netlify.com/sites/ngrx-io/deploys/626b136e85eb120009631713

[markostanimirovic]

There was the same bug with generating API docs for the createActionGroup function as there was for the createFeature - template literal types. I moved its types to another file to make API generation work.

[Xapuu]

I've been doing a version of this for years on my own in each NGRX project that I've worked on, so I'm beyond happy to find out that this is part of the core lib now 🎉
Just wanted to say thanks for adding this feature.