core: Move ResourceManager to batch update VdsDynamic

There is a TODO in ResourceManager to allow batch updates of VdsDynamic
this patch introduces MassOperations to VdsDynamic and allow batch updates
of it. I also changed ResourceManager to use the batch capability.

Change-Id: If857a328d591f87cf453f1620f134d5e0a137363
Bug-Url: https://bugzilla.redhat.com/??????
Signed-off-by: lzelkha@redhat.com <lzelkha@redhat.com>