Add very error-ful checkJS test for chrome devtools js

[weswigham]

This should help us get some checkJs coverage on a project that has some seriously complete jsdoc (as it's validated under closure compiler's strictest mode).

On that note, this depends on #19980 (since it triggers it), and contains errors which are examples of #19990, #19988, #19987, #19986, #19985, #19983, #19982, and #19981. Because those are all parse errors (we probably shouldn't let jsdoc parse errors block semantic analysis), we don't even actually know any type errors that may or may not be correct yet.

[mhegazy]

That is a lot of jsdoc parse errors ..

[weswigham]

@mhegazy Indeed. I also found #20000 using discord.js's source (which I plan to add - it's pretty well structured and uses classes while also using common commonjs patterns, and it gives us a chance to verify the js as we understand it against the .d.ts). Also, I opened #19999 to discuss swallowing jsdoc parse errors unless some kind of --ultraStrictJSDoc flag is passed.