Clean bdms and networks after deleting shelved VM

After deleting the shelved offloaded instance with user volumes,
the bdms and networks info should be cleanup. This patch use local
deleting to cleanup the instance info.

Change-Id: Id32385df5b20903d7a019c3590432f3fb1133f90
Closes-bug: #1307791
Merge "Clean bdms and networks after deleting shelved VM"