dal: Refactor VmStatic and VmTemplate Daos

Extracted common fields from parameter sources of VmStatic and
VmTemplate to new VmBaseDaoDbFacade.

This new class also inheriths DefaultGenericDaoDbFacade to eliminate
trivial implementations of get, update and delete in both
DaoDbImpls.

Change-Id: Ia8c02c11ededf4dfba67e5cc8598ae90155d7eb5
Signed-off-by: Martin Betak <mbetak@redhat.com>