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-repo-push.svg

@@ -1 +1 @@
-<svg viewBox="0 0 16 16" class="svg octicon-repo-push" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M1 2.5A2.5 2.5 0 013.5 0h8.75a.75.75 0 01.75.75v3.5a.75.75 0 01-1.5 0V1.5h-8a1 1 0 00-1 1v6.708A2.492 2.492 0 013.5 9h3.25a.75.75 0 010 1.5H3.5a1 1 0 100 2h5.75a.75.75 0 010 1.5H3.5A2.5 2.5 0 011 11.5v-9zm13.23 7.79a.75.75 0 001.06-1.06l-2.505-2.505a.75.75 0 00-1.06 0L9.22 9.229a.75.75 0 001.06 1.061l1.225-1.224v6.184a.75.75 0 001.5 0V9.066l1.224 1.224z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-repo-push" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M1 2.5A2.5 2.5 0 0 1 3.5 0h8.75a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0V1.5h-8a1 1 0 0 0-1 1v6.708A2.492 2.492 0 0 1 3.5 9h3.25a.75.75 0 0 1 0 1.5H3.5a1 1 0 1 0 0 2h5.75a.75.75 0 0 1 0 1.5H3.5A2.5 2.5 0 0 1 1 11.5v-9zm13.23 7.79a.75.75 0 0 0 1.06-1.06l-2.505-2.505a.75.75 0 0 0-1.06 0L9.22 9.229a.75.75 0 0 0 1.06 1.061l1.225-1.224v6.184a.75.75 0 0 0 1.5 0V9.066l1.224 1.224z"/></svg>