Add separate utility module for controller and agent

We can figure out later whether & where to re-settle helper functions that end
up in there.

scripts/policy/frameworks/cluster/controller/util.zeek

@@ -0,0 +1,17 @@
+module ClusterController::Util;
+
+export {
+	global set_to_vector: function(ss: set[string]): vector of string;
+}
+
+function set_to_vector(ss: set[string]): vector of string
+	{
+	local res: vector of string;
+
+	for ( s in ss )
+		res[|res|] = s;
+
+	sort(res, strcmp);
+
+	return res;
+	}