[TASK] Harden \TYPO3\CMS\Extbase\Utility\TypeHandlingUtility

- Use strict type mode
- Use type hints whereever possible

Releases: master
Resolves: #87601
Change-Id: I087fcb4a87e12ac3d4345a4514dae674b8551460
Reviewed-on: https://review.typo3.org/59596


Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Andreas Wolf <andreas.wolf@typo3.org>
Reviewed-by: Rudy Gnodde <rgn@windinternet.nl>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Wolf <andreas.wolf@typo3.org>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>