Remove StyleProvider

[gksander]

What is this?

This PR removes the need to wrap your app in StyleProvider. The reason for this change is twofold:

1. It's easier to setup if you don't have to wrap your app. I like that, and then dark mode just sort of "magically" works without the provider.
2. I'm working toward a set of response utilities, where you can apply "classes" based on screen size. This will require a top-level WindowDimensions listener. I'd like to keep things as performant as possible, and not have to deal with Context values changing and triggering cascading re-renders.

This PR also adds a bunch of cleanup around tests.

[gksander]

This file is just from the sample, was just fiddling with some things.

[gksander]

No more Provider wrapper, woot.

[carloskelly13]

Yay!

[gksander]

THE NEXT REDUX!

Jk, this is like the most barebones possible state-management solution. I like it because it's lean, and doesn't require Context.

[carloskelly13]

Can we use the following comment

/**
 * @deprecated This provider should not be used
 */

[carloskelly13]

first time ever seeing private class vars in ts

[gksander]

I just recently started using them, and then realized like half of the class vars I use should be considered private, and I love that there's now an easy way for declaring them as such.

[gksander]

Damn, just now seeing that RNW doesn't support Appearance.addChangeListener, so this is going to fail for RNW 😢

I'm torn on this. I really like this change to the API, but not supporting RNW is a real downside.

UPDATE!

Looks like Appearance.addChangeListener does exist, it just doesn't conform to RN's new API for change listeners (e.g., returning a remove method from the subscription). I've created a PR for RNW to support this.

[carloskelly13]

Just one comment, otherwise looks great.

[atanaskanchev]

LGTM? 🥇