[BUGFIX] Re-Implement record_is_used hook for Fluid-based page view

The hook to determine if child records are used is re-implemented.
This makes the fluid based page module behave like the legacy
PageLayoutView when determining if a record was used, allowing
third party extensions to override the core's "is used?" decision.

Resolves: #90927
Releases: master
Change-Id: Ia72cf7479e04ee9c5ae688cf9c37bed697ac4d3e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64049


Reviewed-by: Kevin Appelt <kevin.appelt@icloud.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Claus Due <claus@phpmind.net>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Claus Due <claus@phpmind.net>
Tested-by: Georg Ringer <georg.ringer@gmail.com>