Use case:
- azure nodes needs the extra python3-swh.objstorage.cloud package (workers,
vault)
- (ceph machines needed pyhon3-swh.objstorage.rados)
Using this new option, `azure_euwest` location defines the extra objstorage
dependency.
Thus rendering obsolete some old extra objstorage_cloud class. With this, this
is no longer needed.