[backport 11.0] Upgrade HTML cleaner to 2.16

Using the <source> element in CKEditor's source view leads to an infinite loop in the third party htmlcleaner library 2.12.

Once in the situation, a restart is the only option.

We need to upgrade that library to at least 2.13, but not to 2.16 because that causes CMS-9791.

With the fix in CMS-10482, the upgrade to 2.16 is now possible.