[TASK] Use more specific array type annotations in GeneralUtility

Having PHPDoc parameter and return type annotations like "string[]"
instead of the generic "array" will help both static code analysers
as well as human readers.

Resolves: #91065
Releases: master, 9.5
Change-Id: I7d39241d81ce607e9ca6050cc82126420e1e756e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64203


Tested-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Jonas Eberle <flightvision@googlemail.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Reviewed-by: Jonas Eberle <flightvision@googlemail.com>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>