Remove unused deps

[axelboc]

Fix #1242

All in all, depcheck did a good job :blush: — I did go over all the deps myself just in case it missed one (it didn't). Do please double check thoroughly.

Unused dependencies

• dustjs-helpers: used but imported with require; kept :green_circle:
• dustjs-linkedin: used but imported with require; kept :green_circle:
• everpolate: unused; removed :wastebasket:
• history: unused; removed :wastebasket:
• jsmpeg: used via ui/src/components/SampleView/jsmpeg.min.js, not via NPM package, which is obsolete compared to jsmpeg.min.js; removed :wastebasket:
• liform-react: unused; removed :wastebasket:
• plotly.js: peer of react-plotly.js; unused; removed :wastebasket:
• popper.js: unused; removed :wastebasket:
• react-clipboard.js: unused; removed :wastebasket:
• react-plotly.js: unused; removed :wastebasket:
• react-router: peer of react-router-dom; used; kept :green_circle:
• react-sticky: unused; removed :wastebasket:
• shortid: unused; removed :wastebasket:
• underscore: unused; removed :wastebasket:
• ws: unused; removed :wastebasket:

Unused devDependencies

• @testing-library/react: unused but should be :joy: ; kept for now :green_circle:
• @testing-library/user-event: unused but should be :joy: ; kept for now :green_circle:
• babel-preset-react-app: direct dep of create-react-app; no need to install ourselves; ~removed~ EDIT: re-added in #1274 :green_circle:
• concurrently: unused; removed :wastebasket:
• less: only one .less file ui/src/components/PeriodicTable/style.less with only a few mixins for CSS browser prefixing; styles should be written in pure CSS; browser prefixing is done automatically by autoprefixer based on browserslists config; removed :wastebasket:
• less-watch-compiler: removed :wastebasket:
• sass: no SASS/SCSS files found; removed :wastebasket:
• wait-on: used in CI to wait for server to start before testing with Cypress; kept :green_circle:
• webpack: dependency of webpack-dev-server; safer to keep in case specified version range matters :green_circle:
• webpack-dev-server: dependency of react-scripts; safer to keep in case specified version range matters :green_circle:

Missing dependencies

All of these are direct dependencies of eslint-config-galex, so no need to install them. :green_circle:

[fabcor-maxiv]

Nice job with the investigation! I will try to give it a check from our side, but there is not much doubt you know this stuff better than we do. : )

[fabcor-maxiv]

Could we get a pre-commit hook or maybe a GitHub Action to make sure it stays clean? Would that make sense?

[marcus-oscarsson]

Nice, well done and big thanks !

[axelboc]

Could we get a pre-commit hook or maybe a GitHub Action to make sure it stays clean? Would that make sense?

Hmm, I feel like it would be a bit brittle and not really worth the effort. An unused dependency just adds a few ms to the installation time; nothing worth worrying about too much in my opinion, especially since it doesn't take long to do a bit of a clean-up like this from time to time.