refactor(component-store): fine-tune effect types

[alex-okrushko]

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?
remove EffectReturnFn and make the effect type stricter and more predictable.
For example, previously if effect was const e = effect((o: Observable<string>) => ....) it was still possible to call e() without passing any strings.

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[x] 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 #

What is the new behavior?

Does this PR introduce a breaking change?

[x] Yes
[ ] No

Some tests needed to be adjusted because we are stricter with types and actually enforce the argument requirement (or enforce not passing one).

Other information

[ngrxbot]

Preview docs changes for fc5af33 at https://previews.ngrx.io/pr2645-fc5af33b/