Diskmanage: introduce ceph info helper

Diskmanage: introduce ceph info helper

so it can be re-used for partitions.

Also changes the regular expression in get_ceph_volume_info to match the full
device/partition name the LV is on. Not only is this needed for partitions,
especially if there's multiple partitions with an OSD, but it also fixes
handling NVMe devices with an OSD as a side effect. Previuosly those were not
detected here, because of the digits in the name, e.g. /dev/nvme0n1

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>