Remove leftover references to coffeescript from comments and docs.

I was looking at the front-end helper spec and noticed some outdated coffeescript refs in it. So I figured it wouldn't hurt to take a few minutes and remove all the coffeescript references in CE that we don't need anymore. 

I didn't touch any coffeescript references that could potentially break anything. Just docs and code comments.

- [x] All builds are passing

See merge request !7151