[FEATURE] URL validator for Extbase

Add a new Extbase validator to check if a value is a valid URL.

Change-Id: Ic4ce6ee0f8a38f082e869c094ae6013493d7fb96
Resolves: #80342
Releases: master
Reviewed-on: https://review.typo3.org/52092


Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>