[TASK] Deprecate TSFE->checkFileInclude

The file inclusion logic within the TypoScriptFrontendController
is not used anymore and can safely be deprecated.

Resolves: #65913
Releases: master
Change-Id: Ib229fd25a560fc2a0520032cb6bc9a358a5b69df
Reviewed-on: http://review.typo3.org/38020


Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>
Reviewed-by: Benjamin Mack <benni@typo3.org>
Tested-by: Benjamin Mack <benni@typo3.org>