Investigate deprecated UIs usage of "stylus" package

[simonswine]

This is a follow up to #4312, we removed stylus from the old UI's imports, as it has been compromised (https://www.npmjs.com/package/stylus?activeTab=readme).

This is a transitive dependency of typescript-plugin-css-modules

=> Found "stylus@0.54.8"
info Reasons this module exists
   - "typescript-plugin-css-modules" depends on it
   - Hoisted from "typescript-plugin-css-modules#stylus"

[korniltsev]

typescript-plugin-css-modules
A TypeScript language service plugin for CSS Modules.

In TypeScript 2.2 and later, developers can enable language service plugins to augment the TypeScript code editing experience. The purpose of this guide is to help you write your own plugin.

IMO we don't need this at all, lets just remove this for eternity?

[aleks-p]

It was introduced in #509, alongside the story books which we removed in #3591. If we don't think there is anything more to do here, we can just close this?