Register Babel in Jest setup to load transformer (#39251)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/39251

As `react-native/babel-preset` is extended to include parts of codegen (written in Flow) via `react-native/babel-plugin-codegen`, we need to register Babel (with a Node JS config) in order to load the `react-native/babel-transformer` that Jest needs to transform RN code when running from source.

(This is *only* relevant to running from source, ie internally at Meta or when developing on a clone of the OSS repo)

Changelog: [Internal]

Reviewed By: huntie

Differential Revision: D48871440

fbshipit-source-id: 2f206b2380d67007e37782f211a6e831b35291f8