RN: Inline `setAndForwardRef` into `createAnimatedComponent.js`
RN: Inline `setAndForwardRef` into `createAnimatedComponent.js`

Summary:
Inlines `setAndForwardRef` into `createAnimatedComponent.js`.

I am planning to delete `setAndForwardRef` because it encourages a subtle bad practice with management of the referential equality of `ref` entities. I am doing this instead of refactoring `createAnimatedComponent` because this legacy implementation is planned to be replaced very soon.

Changelog:
[Internal]

Reviewed By: sammy-SC

Differential Revision: D41205066

fbshipit-source-id: dc481e73a6c4d6acbae530d4da48b3a032575179

facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native