[BUGFIX] Trigger 404 for subpage shortcuts w/o subpages

This patch adds a try/catch around the call in TSFE to get
page and rootline with domain and makes getPageShortcut
function set $this->pageNotFound code, then throw error.

Change-Id: Id6aae04d7b4c2a8b267b0d949c056471c3a6b01b
Releases: master
Resolves: #78831
Reviewed-on: https://review.typo3.org/50805


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christer V <cvi@systime.dk>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Wolfgang Klinger <wolfgang@wazum.com>
Tested-by: Wolfgang Klinger <wolfgang@wazum.com>
Reviewed-by: Tobi Kretschmann <tobi@tobishome.de>
Tested-by: Tobi Kretschmann <tobi@tobishome.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>