core: engine vdc error codes for vdsm sparsify

VDSM virt-sparsify integration added two new errors in
storage_exception.py. This patch adds the respective errors
on the engine side.

Change-Id: If787a4980d6a01bb58ad1646e38ef08090b59f37
Signed-off-by: Utkarsh <utkarshsins@gmail.com>