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 #2839

What is the new behavior?

Can select from multiple selectors. Only distinct changes are output.

// returns `Observable<number, number, number>`
const counterStateWithFunc = store.select(
    (s) => s.counter1,
    (s) => s.counter2,
    (s) => s.counter3
 );

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information