Add support for document instance in React Native (#32260) (#49051)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49051

## Summary

We're adding support for `Document` instances in React Native (as
`ReactNativeDocument` instances) in
https://github.com/facebook/react-native/pull/49012 , which requires the
React Fabric renderer to handle its lifecycle.

This modifies the renderer to create those document instances and
associate them with the React root, and provides a new method for React
Native to access them given its containerTag / rootTag.

## How did you test this change?

Tested e2e in https://github.com/facebook/react-native/pull/49012
manually syncing these changes.

DiffTrain build for [b2357ecd8203341a3668a96d32d68dd519e5430d](https://github.com/facebook/react/commit/b2357ecd8203341a3668a96d32d68dd519e5430d)

Reviewed By: javache

Differential Revision: D68839346

fbshipit-source-id: 589ddce15d0f32ba3eab1c03306c405d38616723