Overlay use alias of frontpage node and not the site root domain

Problem/Motivation

When using a node with an URL alias as frontpage, is the module telling the overlay to use the full URL including URL alias as frontpage URL (e.g. http://www.example.com/my-fancy-frontpage). When Siteimprove is crawling the site are they crawling http://www.example.com and not the full path including the URL alias.

Steps to reproduce

1. Create a new node and add a URL alias
2. Configure Drupal to use your new node as frontpage
3. Check which Siteimprove URL is outputted in the Drupal JavaScript object.

Proposed resolution

When outputting the URL check if the actual page / route is a frontpage. If yes, then output both the frontpage URL and the full URL including alias in the JavaScript object. Use \Drupal::service('path.matcher')->isFrontPage(); to check if the current URL is the frontpage.