Disk move was hardcoded to the QEMU move_disk Proxmox API and was
never reachable in the UI for LXC (no Hardware tab for containers,
and the disk list regex only matched VM device names).
- add move_container_disk() using lxc/{vmid}/move_volume
- add POST /api/{server_id}/container/{vmid}/disk/move endpoint
- route useMoveDisk by instance type (vm vs container prefix)
- recognize rootfs/mp\d+ as LXC disk devices
- add a Move disk card on the Settings tab for LXC instances
- filter target storage list by supported content type
(rootdir for LXC, images for VM) instead of showing all storages
943207b6b7