[TASK] Harden \TYPO3\CMS\Extbase\Persistence\Generic\Mapper\DataMapFactory

- Use strict type mode
- Use type hints whereever possible
- Use type casts according to phpstan results

Releases: master
Resolves: #88663
Change-Id: Ic4cf7fe508f62b2a2fd4d2e809f17628c3ad347b
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61201


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>