Created by: mrmckeb
This PR resolves two issues with CRAv4 and React's new JSX transform - originally implemented in #9645.
- The configuration has been moved to the Babel config, which means it will now work with Jest.
- Conflicting ESLint rules are now automatically disabled.
I made the decision not to share the small helper as I didn't want to add another dependency to babel-preset-react-app and eslint-config-react-app, but that's of course open to discussion/ideas.
Resolves #9772 (closed), resolves #9782 (closed).