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-checklist.svg

@@ -1 +1 @@
-<svg viewBox="0 0 16 16" class="svg octicon-checklist" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M2.5 1.75a.25.25 0 01.25-.25h8.5a.25.25 0 01.25.25v7.736a.75.75 0 101.5 0V1.75A1.75 1.75 0 0011.25 0h-8.5A1.75 1.75 0 001 1.75v11.5c0 .966.784 1.75 1.75 1.75h3.17a.75.75 0 000-1.5H2.75a.25.25 0 01-.25-.25V1.75zM4.75 4a.75.75 0 000 1.5h4.5a.75.75 0 000-1.5h-4.5zM4 7.75A.75.75 0 014.75 7h2a.75.75 0 010 1.5h-2A.75.75 0 014 7.75zm11.774 3.537a.75.75 0 00-1.048-1.074L10.7 14.145 9.281 12.72a.75.75 0 00-1.062 1.058l1.943 1.95a.75.75 0 001.055.008l4.557-4.45z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-checklist" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M2.5 1.75a.25.25 0 0 1 .25-.25h8.5a.25.25 0 0 1 .25.25v7.736a.75.75 0 1 0 1.5 0V1.75A1.75 1.75 0 0 0 11.25 0h-8.5A1.75 1.75 0 0 0 1 1.75v11.5c0 .966.784 1.75 1.75 1.75h3.17a.75.75 0 0 0 0-1.5H2.75a.25.25 0 0 1-.25-.25V1.75zM4.75 4a.75.75 0 0 0 0 1.5h4.5a.75.75 0 0 0 0-1.5h-4.5zM4 7.75A.75.75 0 0 1 4.75 7h2a.75.75 0 0 1 0 1.5h-2A.75.75 0 0 1 4 7.75zm11.774 3.537a.75.75 0 0 0-1.048-1.074L10.7 14.145 9.281 12.72a.75.75 0 0 0-1.062 1.058l1.943 1.95a.75.75 0 0 0 1.055.008l4.557-4.45z"/></svg>