Setup DB Roles for CI DB in gprd

When the CI patroni DB cluster is setup, it will just be empty without any special roles or databases needed for container registry, monitoring or pgbouncer.

This issue is for setting up DB, Roles, extensions and functions as needed.

Acceptance criteria:

• create database gitlabhq_ci
• create roles for registry, pgbouncer, monitoring with needed privileges and passwords
• create extensions
• create functions
• configure postgres-exporter and gitlab-monitor appropriately
• configure gitlab-consul to go against the right db