dillon1000/react

Create `ReactNativeComponent` Abstract Class (#9814)

This creates `ReactNativeComponent`, the modern replacement for `NativeMethodsMixin`.

This class is going to allow us to start migrating React Native off `React.createClass(...)` into a typesafe, class-based brave new world.

This also introduces `IReactNativeComponent`, an interface that enforces consistency between `ReactNativeComponent` and `ReactNativeFiberHostComponent`.