postgres: add LB for external connections

postgres/config/clusters/main.yaml

@@ -21,6 +21,14 @@ spec:
       metrics_enabled: "true"
 
   managed:
+    services:
+      additional:
+        - selectorType: rw
+          serviceTemplate:
+            metadata:
+              name: weyma-pgsql-ext
+            spec:
+              type: LoadBalancer
     roles:
     - name: williamp
       ensure: present