Allow parsing lists of compound data types (#49188)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49188

This allows creating lists of a compound data type, storing each element as a variant of the possible types, instead of as the specified type.

Changelog: [Internal]

Reviewed By: lenaic

Differential Revision: D69142157

fbshipit-source-id: d742d81a6517b24f24827727cd777550f2ad274f