mgr/node-proxy: fix "ceph orch hardware status --category criticals"

mgr/node-proxy: fix "ceph orch hardware status --category criticals"

The criticals path was using the wrong data shape:
node-proxy sends status as:

  component -> sys_id -> member

 but the code assumed:

  sys_id -> component -> member

This fixes get_critical_from_host() and _criticals_table() to iterate
in the correct order and build the criticals result with the right
nesting.

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