node-proxy: fix NodeProxySpec deserialization from JSON

node-proxy: fix NodeProxySpec deserialization from JSON

NodeProxySpec.__init__() only accepts service_type and placement,
but ServiceSpec.from_json() passes all stored fields (ssl,
certificate_source, unmanaged, ...)

This breaks 'ceph orch ls' after the mgr reloads a node-proxy spec.

This commit forwards the standard ServiceSpec parameters to the
parent.

Fixes: https://tracker.ceph.com/issues/77874
Signed-off-by: Guillaume Abrioux <gabrioux@ibm.com>