Deletion should only hide documents and attachments but not delete them

Currently documents or attachments are physically deleted. It would be better if the deletion was a "false" deletion since this would allow to rollback deletions.
One simple way to do it for content would be to just empty the document and still keep him there. That would be a different "delete" feature than the current one.
For attachments they would need to be "marked" deleted and their content emptied so that it is not searchable.

Another solution would be to move the documents to a trash space