[DOCS] Adjust getQueryArguments / addQueryString documentation

Resolves: #98507
Related: #98488
Releases: main
Change-Id: Id947f9b9ca75fa97b4f3fd2d270e0d92ac6a88e3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75947


Tested-by: core-ci <typo3@b13.com>
Tested-by: Kevin Appelt <kevin.appelt@icloud.com>
Tested-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Kevin Appelt <kevin.appelt@icloud.com>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>