data-quality postgresql version selectable (#529)

I merge this as is quite safe, tested and I need to do a release including it. Please feel free to comment.

ansible/data_quality_filter_service.yml

@@ -3,7 +3,7 @@
     - common
     - java
     - {role: db-backup, db: postgres, db_name: "{{ dq_db_name }}", db_user: "{{ dq_db_user }}", db_password: "{{ dq_db_password }}" }
-    - {role: postgresql, pg_version: "13"}
+    - {role: postgresql, pg_version: "{{ data_quality_pg_version | default('13') }}"}
     - {role: pg_instance, extensions: [], db_name: "{{ dq_db_name }}", db_user: "{{ dq_db_user }}", db_password: "{{ dq_db_password }}" }
     - tomcat
     - webserver