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-cross-reference.svg

@@ -1 +1 @@
-<svg viewBox="0 0 16 16" class="svg octicon-cross-reference" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M16 1.25v4.146a.25.25 0 01-.427.177L14.03 4.03l-3.75 3.75a.75.75 0 11-1.06-1.06l3.75-3.75-1.543-1.543A.25.25 0 0111.604 1h4.146a.25.25 0 01.25.25zM2.75 3.5a.25.25 0 00-.25.25v7.5c0 .138.112.25.25.25h2a.75.75 0 01.75.75v2.19l2.72-2.72a.75.75 0 01.53-.22h4.5a.25.25 0 00.25-.25v-2.5a.75.75 0 111.5 0v2.5A1.75 1.75 0 0113.25 13H9.06l-2.573 2.573A1.457 1.457 0 014 14.543V13H2.75A1.75 1.75 0 011 11.25v-7.5C1 2.784 1.784 2 2.75 2h5.5a.75.75 0 010 1.5h-5.5z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-cross-reference" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M16 1.25v4.146a.25.25 0 0 1-.427.177L14.03 4.03l-3.75 3.75a.75.75 0 1 1-1.06-1.06l3.75-3.75-1.543-1.543A.25.25 0 0 1 11.604 1h4.146a.25.25 0 0 1 .25.25zM2.75 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.75.75 0 0 1 .53-.22h4.5a.25.25 0 0 0 .25-.25v-2.5a.75.75 0 1 1 1.5 0v2.5A1.75 1.75 0 0 1 13.25 13H9.06l-2.573 2.573A1.457 1.457 0 0 1 4 14.543V13H2.75A1.75 1.75 0 0 1 1 11.25v-7.5C1 2.784 1.784 2 2.75 2h5.5a.75.75 0 0 1 0 1.5h-5.5z"/></svg>