[TASK] Use native types for internal Fluid classes and methods

Also fix some types as needed.

Resolves: #100134
Releases: main
Change-Id: I87cebe0a3a7e3cb97a9a1802640ed856d7939f39
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78085


Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Jörg Bösche <typo3@joergboesche.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>