[FEATURE] Add hook in csc to allow alternative renderings

This hook is needed to render alternative content which is not
just a plain image. I am thinking of showing other FAL content
like videos, things which need to be embedded as JS, ...

Change-Id: Id1f3a21dfbb11fb88fd9384acdd29b445efd4671
Resolves: #46259
Releases: 6.1
Reviewed-on: https://review.typo3.org/18893
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer