[BUGFIX] Do not render a-tag if URL is empty in link.action VH

If the URL cannot be calculated by the UriBuilder an empty URL
is returned. In this case no a-tag is rendered to avoid links
with an empty href-attribute.

Resolves: #90857
Releases: master, 9.5, 8.7
Change-Id: I597a4b11d986a3b6155a695e6fd3c84a94588a1a
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63953


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Johannes Kasberger <johannes.kasberger@reelworx.at>
Tested-by: Frank Nägler <frank.naegler@typo3.org>
Reviewed-by: Johannes Kasberger <johannes.kasberger@reelworx.at>
Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Reviewed-by: Frank Nägler <frank.naegler@typo3.org>