[TASK] Add type hints and fix PHPDoc in extbase DataMapFactory

While this is technically a breaking change it only affects internal API.

Releases: master, 8.7
Resolves: #81336
Change-Id: I700caafcfe7f889bba90c03ae7f7010d8228c64a
Reviewed-on: https://review.typo3.org/52937


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>