dillon1000/react

Convert the rest of react-dom and react-test-renderer to Named Exports (#18145)

Nothing interesting here except that ReactShallowRenderer currently exports
a class with a static method instead of an object.

I think the public API is probably just meant to be createRenderer but
currently the whole class is exposed. So this means that we have to keep
it as default export. We could potentially also expose a named export for
createRenderer but that's going to cause compatibility issues.

So I'm just going to make that export default.

Unfortunately Rollup and Babel (which powers Jest) disagree on how to
import this. So to make it work I had to move the jest tests to imports.

This doesn't work with module resetting. Some tests weren't doing that
anyway and the rest is just testing ReactShallowRenderer so meh.