Improve consumption of RxApp Scheduler properties

[Cheesebaron]

Is your feature request related to a problem? Please describe.

When you use RxApp.MainThreadScheduler or RxApp.TaskpoolScheduler in your code, since the entire RxApp class is marked with RequiresUnreferencedCode attribute, the code that consumes these schedulers requires the same treatment.

This is particular not nice, when creating observables in ViewModels, Repositories or other deeper code, which is then consumed by multiple sources as it forces all consumers to add RequiresUnreferencedCode attibutes.

Describe the solution you'd like

Instead if RxApp, either could avoid being marked with the RequiresUnreferencedCode attribute or the schedulers that live in RxApp could be moved out. That would be much nicer as consumer.

It appears to me RxApp has been marked with RequiresUnreferencedCode due to Splat locator code requiring it. However, the schedulers in particular do not seem to require unreferenced code.

[glennawatson]

Yeah. Lot of cleaning up or the attributes yet to come. We need to cleanup the splat locator.

Thanks for the bug report.