Checking security service is not used while deleting

Added db method share_network_get_all_by_security_service that
returns all share networks to which security service is assigned.

Added check to delete method in security service api that
gets list of share networks that security service is assigned at
and raises error if this list is not empty.

Closes-bug: 1304473

Change-Id: Ibb73f77095b035f33376aa1791448de3a1ed939b