[TASK] Do not implement DAM hook in TYPO3 6.x

DAM does not work with TYPO3 6.x and it will not be adapted
since the main parts of it are now provided by FAL.

EXT:media aims at filling the gap between FAL and current
feature set of DAM in TYPO3 6.x.

Change-Id: I4678114bb51979ed965cadef476b604818ad3485
Resolves: #56616
Reviewed-on: https://review.typo3.org/28185
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers