api: ceph: add ceph/cfg path, deprecate ceph/config and ceph/configdb

api: ceph: add ceph/cfg path, deprecate ceph/config and ceph/configdb

Consolidating the different config paths lets us add more as needed
without polluting our API with too many 'configxxx' endpoints.

The config and configdb paths are renamed under the ceph/cfg path:
* config -> raw (returns the ceph.conf file as is)
* configdb -> db (returns the ceph config db contents)

The old paths are still available and need to be dropped at some point.

Signed-off-by: Aaron Lauterer <a.lauterer@proxmox.com>
Reviewed-by: Dominik Csapak <d.csapak@proxmox.com>
Tested-by:  Dominik Csapak <d.csapak@proxmox.com>