ceph: 12.2.7 -> 13.2.4

* maintain only one version
* ceph-client: init
* include ceph-volume python tool in output

nixos/ceph: extraConfig, fix test, wait for ceph-mgr to become active

* run ceph with disk group permission
* add extraConfig option for the global section
needed per cluster
* clear up how ceph.conf is generated
* fix ceph testcase