Fix scroll when loading.js/ts is used (#48986)
### What?
Whenever you navigated and a page suspended through `loading` or an error happened caught by `error` in the first level of segments (e.g. `/dashboard` but not `/dashboard/settings`) scroll would not be applied. This happened because the focus and scroll handling component is rendered as part of `InnerLayoutRouter` and the Suspense / Error boundary was rendered **around** `InnerLayoutRouter`. This behavior is incorrect as we still want to immediately scroll to the place where the loading is rendered.
This PR fixes the behavior by allowing the scroll to apply to loading / error too.
### How?
Moved the scrolling component around the loading/error/innerlayout boundary and added tests.
