feat(vm-provision): provision FreeBSD and OpenBSD guests

create_vm_from_cloud_init(guest_os=...) with GUEST_AGENTS from
napalm-device-types 3.0 (QEMU_GUEST_AGENTS: Linux, FreeBSD, OpenBSD). An
unknown guest_os is refused before anything is created. Found on FreeBSD
15.1 and OpenBSD 7.9 cloud images (NetOrk/netork#793):

- OS type `other` for the BSDs. OpenBSD's qemu-ga only works over ISA
  serial, and only as the second port: the image keeps its console on
  com0, so the VM gets `serial0: socket` next to `agent: 1,type=isa`.
- A BSD guest gets a network-config v2 snippet of its own
  (`cicustom: user=...,network=...`, MAC read back from net0). FreeBSD's
  nuageinit fails on the v1 Proxmox generates and then skips runcmd,
  which starts the guest agent. Linux keeps Proxmox's own.
- Packed images (FreeBSD's .qcow2.xz) are unpacked on the node after the
  packed file's checksum is verified; only the unpacked file is cached.
  download-url unpacks ISOs only, so they always take the SSH path.

Fixed on the way:
- get_vm_status skipped loopback only when it was called `lo`; OpenBSD's
  agent lists `lo0` first, so 127.0.0.1 would have been the VM's IP.
  Loopback is now recognised by its address.
- destroy_vm read cicustom after deleting the VM, when its config was gone,
  so snippets stayed on the node; it now reads them first and removes all
  of them (#15).

CHANGELOG.md

@@ -8,6 +8,23 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- FreeBSD and OpenBSD guests: `create_vm_from_cloud_init(guest_os=...)` with
+  `GUEST_AGENTS` from napalm-device-types 3.0. A BSD guest gets OS type
+  `other` and a network-config v2 snippet of its own (`cicustom network=`),
+  because FreeBSD's nuageinit skips runcmd on the v1 Proxmox generates.
+  OpenBSD's agent runs over ISA serial behind `serial0`, as the image keeps
+  its console on com0. An unknown `guest_os` is refused before anything is
+  created.
+- Packed cloud images (FreeBSD's `.qcow2.xz`) are unpacked on the node after
+  the packed file's checksum is verified; only the unpacked file is cached.
+  Proxmox's `download-url` unpacks ISOs only, so they always go over SSH.
+
+### Fixed
+- `get_vm_status` no longer reports a loopback address as the VM's IP when
+  the agent lists loopback under another name than `lo` (`lo0` on the BSDs,
+  listed first by OpenBSD).
+- `destroy_vm` reads the VM's cloud-init snippets before deleting the VM, and
+  removes all of them; it read them afterwards, when the config was gone (#15).
 - Cloud images for `create_vm_from_cloud_init` are downloaded by Proxmox itself
   when the node has an active storage with content type `import` (Proxmox
   8.2+): `download-url` with checksum verification, then `import-from` as the