Handle "empty" render() calls in noInline mode

[wagerfield]

When noInline mode is enabled and you call render with no arguments, React throws the error: https://reactjs.org/docs/error-decoder.html/?invariant=152&args[]=n

This can be seen on the React Live demo site if you scroll to the last example and delete the contents of the render call.

You get "An unexpected error has occurred." printed to the screen and there's no going back. You have to refresh the page to remedy this error.

It would be better if React live gracefully caught this error and printed it to LiveError in the same way that it does when the code is set to an empty string in "normal/inline" mode.

[wagerfield]

For the time being I'm using transformCode to replace empty render calls with render(null)

const transformCode = (code) => {
  return code.replace(/render\(\s*\)/, "render(null)")
}

...but I think an error should still be thrown that's caught by LiveError