qemu: Add support for networked disks for block pull/block rebase
qemu: Add support for networked disks for block pull/block rebase

Now that we are able to select images from the backing chain via indexed
access we should also convert possible network sources to
qemu-compatible strings before passing them to qemu.

agx/libvirt,taget/libvirt,crobinso/libvirt,olafhering/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,elmarco/libvirt,shugaoye/libvirt,libvirt/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,agx/libvirt,jfehlig/libvirt,eskultety/libvirt,elmarco/libvirt,VenkatDatta/libvirt,taget/libvirt,libvirt/libvirt,elmarco/libvirt,nertpinx/libvirt,zippy2/libvirt,shugaoye/libvirt,libvirt/libvirt,eskultety/libvirt,taget/libvirt,andreabolognani/libvirt,crobinso/libvirt,shugaoye/libvirt,fabianfreyer/libvirt,libvirt/libvirt,agx/libvirt,datto/libvirt,andreabolognani/libvirt,zippy2/libvirt,olafhering/libvirt,zippy2/libvirt,jardasgit/libvirt,rlaager/libvirt,VenkatDatta/libvirt,crobinso/libvirt,jfehlig/libvirt,elmarco/libvirt,eskultety/libvirt,andreabolognani/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,eskultety/libvirt,jardasgit/libvirt,agx/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,datto/libvirt,rlaager/libvirt,taget/libvirt,jardasgit/libvirt,taget/libvirt,rlaager/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,rlaager/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,datto/libvirt,olafhering/libvirt,zippy2/libvirt,rlaager/libvirt,datto/libvirt,andreabolognani/libvirt,shugaoye/libvirt,elmarco/libvirt,datto/libvirt,jfehlig/libvirt,crobinso/libvirt,eskultety/libvirt,agx/libvirt,olafhering/libvirt,shugaoye/libvirt