Convert all uses of Scheduler with a custom class that implements SchedulerLike

[benjamincharity]

NGRX is throwing this error when linting:

Scheduler is deprecated: Scheduler is an internal implementation detail of RxJS, and
should not be used directly. Rather, create your own class and implement
{@link SchedulerLike}

• Create class that implements SchedulerLike
• Replace all uses of Scheduler with the new class