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-fold.svg

@@ -1 +1 @@
-<svg viewBox="0 0 16 16" class="svg octicon-fold" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M10.896 2H8.75V.75a.75.75 0 00-1.5 0V2H5.104a.25.25 0 00-.177.427l2.896 2.896a.25.25 0 00.354 0l2.896-2.896A.25.25 0 0010.896 2zM8.75 15.25a.75.75 0 01-1.5 0V14H5.104a.25.25 0 01-.177-.427l2.896-2.896a.25.25 0 01.354 0l2.896 2.896a.25.25 0 01-.177.427H8.75v1.25zm-6.5-6.5a.75.75 0 000-1.5h-.5a.75.75 0 000 1.5h.5zM6 8a.75.75 0 01-.75.75h-.5a.75.75 0 010-1.5h.5A.75.75 0 016 8zm2.25.75a.75.75 0 000-1.5h-.5a.75.75 0 000 1.5h.5zM12 8a.75.75 0 01-.75.75h-.5a.75.75 0 010-1.5h.5A.75.75 0 0112 8zm2.25.75a.75.75 0 000-1.5h-.5a.75.75 0 000 1.5h.5z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-fold" width="16" height="16" aria-hidden="true"><path d="M10.896 2H8.75V.75a.75.75 0 0 0-1.5 0V2H5.104a.25.25 0 0 0-.177.427l2.896 2.896a.25.25 0 0 0 .354 0l2.896-2.896A.25.25 0 0 0 10.896 2zM8.75 15.25a.75.75 0 0 1-1.5 0V14H5.104a.25.25 0 0 1-.177-.427l2.896-2.896a.25.25 0 0 1 .354 0l2.896 2.896a.25.25 0 0 1-.177.427H8.75v1.25zm-6.5-6.5a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5zM6 8a.75.75 0 0 1-.75.75h-.5a.75.75 0 0 1 0-1.5h.5A.75.75 0 0 1 6 8zm2.25.75a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5zM12 8a.75.75 0 0 1-.75.75h-.5a.75.75 0 0 1 0-1.5h.5A.75.75 0 0 1 12 8zm2.25.75a.75.75 0 0 0 0-1.5h-.5a.75.75 0 0 0 0 1.5h.5z"/></svg>