[BUGFIX] Avoid E_DEPRECATED error calling trim(null) and explode(null)

TypoScriptTemplateInformationModuleFunctionController::main() calls
trim() and explode() with array values which may be null. Feeding null
for the string arguments of these functions emits a E_DEPRECATED
PHP 8.1 error. Sanitize calls.

Resolves: #95936
Releases: master
Change-Id: I03d9f5db9e0688c0de21db1305fce431804d1d26
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72133


Tested-by: core-ci <typo3@b13.com>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>