This change integrates changes related to the new Patroni-enabled
high availability included in the postgresql helm chart.
1. Updates the version of the postgresql chart
2. Adds users/passphrases for the postgresql replication and exporter users
3. Sets the default number of replicas to 3 (except for skiff & sloop)
4. Adds documentation/scripting for upgrading the chart
Co-Authored-By: Evgeniy L <email@example.com>