infra: rename osd-configure to add-osd and improve it
The playbook has various improvements:
* run ceph-validate role before doing anything
* run ceph-fetch-keys only on the first monitor of the inventory list
* set noup flag so PGs get distributed once all the new OSDs have been
added to the cluster and unset it when they are up and running
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1624962 Signed-off-by: Sébastien Han <seb@redhat.com>