[TASK] Create CSS Styled Content TypoScript configuration for 6.3

For backwards compatibility we keep versions of the CSS Styled
Content TypoScript configuration files selectable as rendering
template.

The current setup.txt and constants.txt are just copied into
the 6.2 folder. After this change the branches may diverge.

Resolves: #59736
Releases: 6.3
Change-Id: Ic8ec99917917678c6d0e38ca7b4402166ffac115
Reviewed-on: https://review.typo3.org/30957
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring