Update JS dependencies (#15033)

* Update JS dependencies

- Update all JS dependencies
- For octicons, rename trashcan to trash
- For svgo, migrate to v2 api, output seems to have slightly changed but icons look the same
- For stylelint, update config, fix custom property duplicates
- For monaco, drop legacy Edge support
- For eslint, enable new rules, fix new issues
- For less-loader, remove deprecated import syntax

* update svgo usage in generate-images and rebuild logo.svg with it

public/img/svg/octicon-git-compare.svg

@@ -1 +1 @@
-<svg viewBox="0 0 16 16" class="svg octicon-git-compare" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M9.573.677L7.177 3.073a.25.25 0 000 .354l2.396 2.396A.25.25 0 0010 5.646V4h1a1 1 0 011 1v5.628a2.251 2.251 0 101.5 0V5A2.5 2.5 0 0011 2.5h-1V.854a.25.25 0 00-.427-.177zM6 12v-1.646a.25.25 0 01.427-.177l2.396 2.396a.25.25 0 010 .354l-2.396 2.396A.25.25 0 016 15.146V13.5H5A2.5 2.5 0 012.5 11V5.372a2.25 2.25 0 111.5 0V11a1 1 0 001 1h1zm6.75 0a.75.75 0 100 1.5.75.75 0 000-1.5zM4 3.25a.75.75 0 11-1.5 0 .75.75 0 011.5 0z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-git-compare" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M9.573.677 7.177 3.073a.25.25 0 0 0 0 .354l2.396 2.396A.25.25 0 0 0 10 5.646V4h1a1 1 0 0 1 1 1v5.628a2.251 2.251 0 1 0 1.5 0V5A2.5 2.5 0 0 0 11 2.5h-1V.854a.25.25 0 0 0-.427-.177zM6 12v-1.646a.25.25 0 0 1 .427-.177l2.396 2.396a.25.25 0 0 1 0 .354l-2.396 2.396A.25.25 0 0 1 6 15.146V13.5H5A2.5 2.5 0 0 1 2.5 11V5.372a2.25 2.25 0 1 1 1.5 0V11a1 1 0 0 0 1 1h1zm6.75 0a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5zM4 3.25a.75.75 0 1 1-1.5 0 .75.75 0 0 1 1.5 0z"/></svg>