qubes/storage: allow passing just volume name to storage.resize
qubes/storage: allow passing just volume name to storage.resize

It makes much more sense to call:

    vm.storage.resize('private', 10000000000)

instead of:

    vm.storage.resize(vm.volumes['private'], 10000000000)

QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,woju/qubes-core-admin,QubesOS/qubes-core-admin