Created by: rovansteen
This is a partial implementation of #6116. Because there are still a number of things that need to be figured about alias support I think it will be the best approach to add support for baseUrl first.
This will be a breaking change and removes support for setting NODE_PATH in .env file in favor of setting baseUrl in either jsconfig.json or tsconfig.json. It adds a warning to the start script to inform the user about this change if there is a NODE_PATH value in process.env.
This PR aims to add the existing behavior of resolving modules with absolute path that already exists in CRA but in a consistent manner for both TypeScript and JavaScript projects.
Since this is a breaking change it would be nice to get this in with 3.0. After that we can create another PR to add support for aliases (like @) since that would be a non-breaking change.