Previously, when navigating to a new page via a link, the scroll
position was correctly restored to 0, but navigating to a new page via
typing the URL in the browser address bar keeps the old scroll position.
This commit ensures that the scroll position is restored to 0 whenever
the `ScrollService` is instantiated anew (i.e. new page navigation). The
old behavior of retaining the scroll position on reload is kept by
storing the old URL when leaving a page and only applying the stored
scroll position if the new URL matches the stored one.
Fixes#33260
PR Close#33344
