[!!!][TASK] Remove deprecated TSFE properties

The unused properties are removed

* $TSFE->divSection
* $TSFE->domainStartPage
* $TSFE->fePreview
* $TSFE->sys_language_isocode

Resolves: #91524
Related: #91473
Releases: master
Change-Id: Iab287f24c45442ce39e82a9ca24c696240f41614
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64613


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>