[TASK] Move TSFE->getPageShortcut to PageRepository

The method `getPageShortcut()` which is marked as private is moved to
PageRepository, as it only requires logic and methods from
PageRepository.

Resolves: #85130
Releases: master
Change-Id: I4c7296e085953377e0937b8d1efad0b97d1fb021
Reviewed-on: https://review.typo3.org/57106


Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>