Allow analysis of generated bundle and dependencies

Created by: valscion

This issue is a continuation from the Twitter thread discussing usage of webpack-bundle-analyzer with CRA.

webpack-bundle-analyzer can be used either as a CLI, providing it the stats.json webpack JSON output and the built files. With these, we are able to:

1. Show the sizes of each module as they are on disk
2. Show the sizes of each module after minifcation
3. Show the sizes of each module after minification and gzip

Here's an example I built from a project using create-react-app after first having to eject.

⏩ report.html.zip ⏪

The changes I had to do after ejecting are in this commit: https://github.com/valscion/arvontakone/commit/fbbc3069ef7a152bce6eb2087d91beeda7a9ec36

EDIT: Here's a GIF of that visualization: