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-archive.svg

@@ -1 +1 @@
-<svg viewBox="0 0 16 16" class="svg octicon-archive" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M1.75 2.5a.25.25 0 00-.25.25v1.5c0 .138.112.25.25.25h12.5a.25.25 0 00.25-.25v-1.5a.25.25 0 00-.25-.25H1.75zM0 2.75C0 1.784.784 1 1.75 1h12.5c.966 0 1.75.784 1.75 1.75v1.5A1.75 1.75 0 0114.25 6H1.75A1.75 1.75 0 010 4.25v-1.5zM1.75 7a.75.75 0 01.75.75v5.5c0 .138.112.25.25.25h10.5a.25.25 0 00.25-.25v-5.5a.75.75 0 111.5 0v5.5A1.75 1.75 0 0113.25 15H2.75A1.75 1.75 0 011 13.25v-5.5A.75.75 0 011.75 7zm4.5 1a.75.75 0 000 1.5h3.5a.75.75 0 100-1.5h-3.5z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-archive" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M1.75 2.5a.25.25 0 0 0-.25.25v1.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25v-1.5a.25.25 0 0 0-.25-.25H1.75zM0 2.75C0 1.784.784 1 1.75 1h12.5c.966 0 1.75.784 1.75 1.75v1.5A1.75 1.75 0 0 1 14.25 6H1.75A1.75 1.75 0 0 1 0 4.25v-1.5zM1.75 7a.75.75 0 0 1 .75.75v5.5c0 .138.112.25.25.25h10.5a.25.25 0 0 0 .25-.25v-5.5a.75.75 0 1 1 1.5 0v5.5A1.75 1.75 0 0 1 13.25 15H2.75A1.75 1.75 0 0 1 1 13.25v-5.5A.75.75 0 0 1 1.75 7zm4.5 1a.75.75 0 0 0 0 1.5h3.5a.75.75 0 1 0 0-1.5h-3.5z"/></svg>