This also changes the return values, since their meanings are rather
weird from the storage point of view. For instance, "internal" meant
it is *not* the storage which does the snapshot, while "external"
meant a mixture of storage and qemu-server side actions. `undef` meant
the storage does it all...
┌────────────┬───────────┐
│ previous │ new │
├────────────┼───────────┤
│ "internal" │ "qemu" │
│ "external" │ "mixed" │
│ undef │ "storage" │
└────────────┴───────────┘
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
41c6e4bf7a