f:link.action renders invalid links if pageUid param is omitted
Due to #81213, the pageUid parameter in f:link.action is now always casted to an int. This leads to unwanted behaviour, as pageUid is 0 in such case, causing to break
UriBuilder->uriFor() as the pageUid is checked for
null. As null !== 0, the page uid is not determined correctly, causing typolink_URL to render empty strings.
This may be tested with EXT:indexed_search, the "Advanced search" link is broken and always links to the current page.
Side effect: submitting its form and clicking "Advanced search" then, exceptions occur.