perf(component): do not schedule render for synchronous events

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

What is the current behavior?

The render scheduler unnecessarily schedules render/marks a component as dirty when synchronous events are emitted.

For instance, in the following example:

@Component({
  template: `
    <p>{{ obs$ | ngrxPush }}</p>
  `
})
export class TestComponent {
  obs$ = of(1, 2, 3);
}

The PushPipe will mark TestComponent as dirty (and schedule tick in zone-less mode) 4 times (3 next, and 1 complete event) which is not needed because all these events will be emitted synchronously, so the last value will be visible in the template without scheduling render/marking it as dirty.

What is the new behavior?

The render scheduler schedules render/marks a component as dirty only when asynchronous events are emitted.

• Zone-Full Playground
• Zone-Less Playground

Does this PR introduce a breaking change?

[ ] Yes
[x] No

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[markostanimirovic]

There is no need to schedule render for suspense events at all, because suspense events are synchronous.