[BUGFIX] Handle missing TSFE gracefully in TS conditions

A condition like [getTSFE().id == 1] is evaluated in BE as well
and logged an error 'Unable to get a property on a non-object'.

This patch ensures that conditions based on getTSFE() are
treated gracefully and are evaluated to false.

Resolves: #87021
Releases: master, 9.5
Change-Id: If56a8b7bd66b9f7e66bdc8ce5f56c8df890cf655
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/59129


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Susanne Moog <look@susi.dev>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>