Update node packages and remove unneeded ones (#1258)

* changes induced by npm audit fix --force

* bump webpack

* fix webpack errors

- update CopyPlugin syntax
- bump webpack-cli

* remove stale deps

* switch our CSS minimizer

* fix sass load failure

* fix compile fail false alarm (#{} in comment)

* fix SASS compile fail (@use X as *)

* commit package-lock

* remove file loader and other unused

* restore sass; update package-lock

* Update webpack.config.js

Co-authored-by: gabalafou <gabriel@fouasnon.com>

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Co-authored-by: gabalafou <gabriel@fouasnon.com>