CLOUDSTACK-2029 zone wide primary storage support for cloudstack over vmware deployments

Added hypervisor type to CreateStoragePoolCmd & Storage pool responses.
DatastoreLifeCycle would consider hypervisor type while attaching datastore to zone.
ZoneWideStoragePoolAllocator would filter zone wide primary storage pools by hypervisor type along with tags in disk profile.
hypervisor type is mandatory parameter if scope is specified as ZONE while creating primary storage pool.
As of now KVM, VMware are allowed to use ZoneWideStoragePoolAllocator.