[TASK] Correct incomplete doc types

ExtensionStatus::getStatus()'s doc type does not account for
the use of [] as a sentinel value.

The extra doc type declaration in
FolderBasedFileCollection::fromArray() is incorrect, as it
does not account for null return values.

Used command:

> ./Build/Scripts/runTests.sh -s phpstanGenerateBaseline

Resolves: #98003
Releases: main, 11.5
Change-Id: Ifaad71a8e65836e943b1a3813f3294e7421c5402
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75264


Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>