[!!!][TASK] PageRenderer should only render a full page

PageRenderer->render() does not accept any arguments anymore.

This change allows to later-on hand in a Request object
into the PageRenderer and/or continue building a generic
View for rendering content, without marker-based changes.

In addition, the corresponding constants are now marked as
protected.

Resolves: #93003
Releases: master
Change-Id: Ia24c81647d665fdc23a8c961fe89722cf0e5a31d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/67033


Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>