Use cookie-access rights for webcontent settings

This ties the indexed-db, DOM storage and filesystem access to
cookie rights as they can all do the same cookies. A previous
patch did the same for workers, but we were missing this
class to complete the logic.

Change-Id: I5ea894b6c631bcf25439759174866d260b91b71a
Reviewed-by: Peter Varga <pvarga@inf.u-szeged.hu>