node-proxy: normalize storage data per member

node-proxy: normalize storage data per member

Let's apply normalize_dict() to each member's data only, so the first
level keys (that are redfish member identifiers like "Self") are not
lowercased.

This avoids duplicate entries in hardware status.

Example:

```
[root@node-proxy-1 cephadm]# ./cephadm shell -- ceph orch hardware status --category criticals
Inferring fsid 9d6d6012-067a-11f1-8e61-525400a04a72
Inferring config /var/lib/ceph/9d6d6012-067a-11f1-8e61-525400a04a72/mon.node-proxy-1/config
+--------------+-----------+------+--------+-------+
|     HOST     | COMPONENT | NAME | STATUS | STATE |
+--------------+-----------+------+--------+-------+
| node-proxy-1 |    self   | None |  N/A   |  N/A  |
| node-proxy-1 |    Self   | None |  N/A   |  N/A  |
+--------------+-----------+------+--------+-------+
```

Fixes: https://tracker.ceph.com/issues/74749
Signed-off-by: Guillaume Abrioux <gabrioux@ibm.com>