Handle babel transpilation errors

Code - https://github.com/freeCodeCamp/mobile/blob/e4271d672baa9bbcfa1fbf9f58a570fb0e48004d/mobile-app/lib/ui/views/learn/test_runner.dart#L71

We need to handle this error by showing it to the user and put it in the console tab just like in the website. For now we're throwing it but the user is not aware that their code is incorrect.