[TASK] Bring back int_from_ver

Due to many failing extensions relying on this function,
Release Management decided to bring it back as a redirect
to VersionNumberUtility::convertVersionNumberToInteger.

Resolves: #48536
Relates: #44763
Releases: 6.2, 6.1
Change-Id: Id76758c10a542bdbe0cc033466f494b0a6350692
Reviewed-on: https://review.typo3.org/21519
Reviewed-by: Markus Klein
Tested-by: Markus Klein