Webpack sw.js improvements

This does the following:

1. Temporarily disables code related to push notifications. They simply don't work yet, so there's no point running this code until we fix it.

2. Refactors Webpack so it treats static as the root path. Previously it would output to static/packs which caused problems.

3. Fix the service worker causing the user's browser to fetch 3000+ emojis on pageload.