clvm package and it executables are missed in the Ubuntu 20.04 LTS

Also missed

```
/lib/systemd/lvm2-cluster-activation
/lib/systemd/system/lvm2-cluster-activation.service
/lib/systemd/system/lvm2-clvmd.service
/lib/systemd/system/lvm2-cmirrord.service
/usr/lib/ocf/resource.d/lvm2/clvmd
```

on 20.04 LTS.

@nrbbrtx:

LVM2 has deprecated clvm in favor of lvmlockd (lvm2-lockd in Focal) only for VG access coordination AND it can use either DLM (dlm-controld) or sanlock (sanlock) as lock managers.

http://manpages.ubuntu.com/manpages/focal/man8/lvmlockd.8.html

From an upstream discussion thread, the lvmlockd benefits over clvm are:

"""
- lvmlockd supports two cluster locking plugins: dlm and sanlock. sanlock plugin can supports up to ~2000 nodes that benefits LVM usage in big virtualization / storage cluster, while dlm plugin fits HA cluster.

- lvmlockd has better design than clvmd. clvmd is command-line level based locking system, which means the whole LVM software will get hang if any LVM command gets dead-locking issue. However, lvmlockd is *resources* based cluster locking. The resources to protect is VG and LV so that the deadlock issue will be isolated inside the resource and
operations on other VG/LV can still proceed.

- lvmlockd can work with lvmetad.
"""

Now, instead of using the clvm pacemaker resource agent, you should use:

lvmlockd agent manages the lvmlockd daemon.

from the available resource agents list:

https://discourse.ubuntu.com/t/ubuntu-ha-pacemaker-resource-agents-supportability/15729