[build-scripts] upgrade webpack deps, adjust karma stylesheets

[adidahiya]

Changes proposed in this pull request:

Upgrade webpack-related dependencies

• https://github.com/TypeStrong/ts-loader/blob/main/CHANGELOG.md
• https://github.com/webpack-contrib/style-loader/blob/master/CHANGELOG.md
• https://github.com/webpack-contrib/sass-loader/blob/master/CHANGELOG.md
• https://github.com/pmmmwh/react-refresh-webpack-plugin/blob/main/CHANGELOG.md
• https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md
• https://cssnano.co/docs/changelog/
• https://github.com/johnnyreilly/fork-ts-checker-notifier-webpack-plugin/blob/master/CHANGELOG.md
• https://github.com/TypeStrong/fork-ts-checker-webpack-plugin/releases/tag/v7.0.0
• https://github.com/webpack-contrib/mini-css-extract-plugin/blob/master/CHANGELOG.md
• https://github.com/webpack-contrib/postcss-loader/blob/master/CHANGELOG.md

Not upgraded: webpack-dev-server (see migration guide)

Fix createKarmaConfig to work outside this repo, loading the core stylesheet from node_modules if necessary

[blueprint-bot]

cleanup lockfile

Previews: documentation | landing | table | modern colors demo