[!!!][TASK] Deprecate FormEngine::renderVDEFDiff()

This patch deprecates FormEngine::renderVDEFDiff() and removes
the dependency from all form element classes.

Resolves: #63864
Releases: master
Change-Id: Ib4dbdddde76554147b1328645e2e90107e2ddbca
Reviewed-on: http://review.typo3.org/35490
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>