create tasks for cron extension

roles/common/tasks/postgres_cron.yml

@@ -41,10 +41,14 @@
     name: postgresql
     state: restarted
 
-- postgresql_query:
-    db: {{ timescaledb_database_name }}
-    login_user: postgres
-    login_password: {{ postgresql_admin_password }}
+- name: "Configure pg_cron extension"
+  tags:
+    - install
+    - timescaledb_install
+  postgresql_query:
+    db: "{{ timescaledb_database_name }}"
+    login_user: "postgres"
+    login_password: "{{ postgresql_admin_password }}"
     query:
       - CREATE EXTENSION pg_cron;
       - GRANT USAGE ON SCHEMA cron TO {{ timescaledb_database_user }};