Restore nextcloud cnpg backup

[Simon-Boyer]

What it does

• Add recovery backup for cnpg nextcloud.
• Sets nextcloud replicas to 0 for db init

How to use

1. Once merged, make sure argo for nextcloud synced and there is now 0 nextcloud replicas
2. Manually delete the cnpg cluster, it needs to be recreated from scratch using the new bootstrap backup config
3. Connecting to cnpg on the nextcloud database, run this command to make sure restore was successful:

SELECT
  (SELECT count(*) FROM oc_users)       AS users,
  (SELECT count(*) FROM oc_appconfig)   AS appconfig,
  (SELECT count(*) FROM oc_storages)    AS storages,
  (SELECT count(*) FROM oc_filecache)   AS filecache;

4. Revert this PR & sync argo

[Simon-Boyer]

looks like it was fine, no restore required