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-code-square.svg

@@ -1 +1 @@
-<svg viewBox="0 0 16 16" class="svg octicon-code-square" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M1.75 1.5a.25.25 0 00-.25.25v12.5c0 .138.112.25.25.25h12.5a.25.25 0 00.25-.25V1.75a.25.25 0 00-.25-.25H1.75zM0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0114.25 16H1.75A1.75 1.75 0 010 14.25V1.75zm9.22 3.72a.75.75 0 000 1.06L10.69 8 9.22 9.47a.75.75 0 101.06 1.06l2-2a.75.75 0 000-1.06l-2-2a.75.75 0 00-1.06 0zM6.78 6.53a.75.75 0 00-1.06-1.06l-2 2a.75.75 0 000 1.06l2 2a.75.75 0 101.06-1.06L5.31 8l1.47-1.47z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-code-square" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M1.75 1.5a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75zM0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75zm9.22 3.72a.75.75 0 0 0 0 1.06L10.69 8 9.22 9.47a.75.75 0 1 0 1.06 1.06l2-2a.75.75 0 0 0 0-1.06l-2-2a.75.75 0 0 0-1.06 0zM6.78 6.53a.75.75 0 0 0-1.06-1.06l-2 2a.75.75 0 0 0 0 1.06l2 2a.75.75 0 1 0 1.06-1.06L5.31 8l1.47-1.47z"/></svg>