feat: implement the HypervisorDriver VM contract

start_vm, stop_vm, reboot_vm, suspend_vm and get_vm_config existed only
as declarations. netOrk called Proxmox's own power_vm and read a VM's
raw config through _node_api(), so no other hypervisor could serve the
same endpoints. These let netOrk talk to every hypervisor alike.

The power methods accept a VM's name or vmid, wait for the Proxmox task,
and raise ValueError/RuntimeError as the contract says instead of
returning a result dict. A forced reboot of a container is stop + start,
since LXC has no reset; suspending a container is refused. power_vm is
unchanged for existing callers.

get_vm_config moves the config parsing netOrk did in
_parse_proxmox_hw_config into the driver and returns a VMConfigDict:
disks with storage and size, NICs with model, MAC, bridge and VLAN, CPU
topology, firmware, machine type and PCI/USB passthrough.

get_vms reports vmid as a string ("100"), following
napalm-device-types 2.0, still ordered numerically.

CHANGELOG.md

@@ -7,6 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- `HypervisorDriver` contract methods `start_vm`, `stop_vm`, `reboot_vm`,
+  `suspend_vm` and `get_vm_config`. They accept a VM's name or vmid, raise
+  `ValueError`/`RuntimeError` instead of returning a result dict, and wait
+  for the Proxmox task to finish. `power_vm` is unchanged.
+
+### Changed
+- `get_vms()` reports `vmid` as a string (`"100"`), following
+  napalm-device-types 2.0. Ordering stays numeric.
+
 ## [0.1.0] - 2024-01-01
 
 ### Added