feat: restore master cs backup cfg on restart

CS backup are stored in .zip files ordered like ../csbackup/<year>/<month>/<configuration-name.cfg@datetime.zip>. When the Master CS pod is recreated the config is not conserved, this leads to DB configuration not found by the other DIRAC services. To fix this we need to keep or restore the config.

To avoid access issue to the config by the master cs when mounting the file direclty from the PV, I prefer to restore the latest config backup on restart.