[BUGFIX] Let all toplevel exceptions extend the core exception

This is a small step to unify exception handling in TYPO3 by
ensuring no internal and 3rd party code is forced to catch the
toplevel PHP exception.

This change e.g. actually allows the FormPagePreviewRenderer to
handle form loading errors.

Resolves: #82052
Releases: master, 8.7
Change-Id: I5cb0b8f2c56a6bbbecc34d87474d6d8b3ad2015c
Reviewed-on: https://review.typo3.org/53651


Reviewed-by: Wolfgang Klinger <wolfgang@wazum.com>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Tested-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>