[TASK] Add missing methods in AbstractRenderable class

This patch adds two methods setDefaultValue and setProperty
which are called from within class AbstractRenderable via
$this->setDefaultValue() and $this->setProperty() but are
meant to be called on a child class.

The implementation of said methods with an empty method body
only serve the purpose to please phpstan. As mentioned in
those method bodies, someone with a deeper understanding of
the form extension architecture needs to decide whether the
abstract class AbstractRenderable should only declare those
methods as abstract methods, i.e. child classes have to
implement them or if the abstract class can provide a
meaningful default behavior which can but doesn't need to
be overridden by child classes.

Releases: master
Resolves: #90385
Change-Id: I1ac3b319746d8eca12b32394cd9da2073431b582
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63262


Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>