In some cases, it is useful to use a relative base href in the app (e.g.
when an app has to be accessible on different URLs, such as on an
intranet and the internet - see #25055 for a related discussion).
Previously, the Angular ServiceWorker was not able to handle relative
base hrefs (for example when building the with `--base-href=./`).
This commit fixes this by normalizing all URLs from the ServiceWorker
configuration wrt the ServiceWorker's scope.
Fixes#25055
PR Close#37922