add a --destroy flag to forcefully remove the underlying vg/lv when zapping
A new flag should be added to `lvm zap` that allows destroying the vg/lv/pv when zapping, since it is possible an operator might
not care about the vg.
ceph-volume does have some simplistic functionality that creates these, so a flag to destroy them (although not by default since it is destructive) would help
avoid having to deal with LVM directly.