m/n/c/curator: add UpdateStatus

This implements Curator.UpdateStatus, which lets nodes self-report some
status items. Currently this is their external IP address, which is
needed to generate a Cluster Directory which is in turn needed to
register into a cluster.

Change-Id: Ib5464ca78ee3466d9b9f89b7af8b40f613ae8dcc
Reviewed-on: https://review.monogon.dev/c/monogon/+/332
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/proto/ext/authorization.proto b/metropolis/proto/ext/authorization.proto
index 2988010..42beb88 100644
--- a/metropolis/proto/ext/authorization.proto
+++ b/metropolis/proto/ext/authorization.proto
@@ -21,6 +21,7 @@
     PERMISSION_UNSPECIFIED = 0;
     PERMISSION_GET_REGISTER_TICKET = 1;
     PERMISSION_READ_CLUSTER_STATUS = 2;
+    PERMISSION_UPDATE_NODE_SELF = 3;
 }
 
 // Authorization policy for an RPC method. This message/API does not have the