Add Praefect database check to Geo setup
Problem to solve
The Praefect database contains internal state information about the Gitaly HA configuration that should not be replicated to other instances, including replica Geo instances.
It is likely that some users will ignore the documentation, or not realize when later configuring Geo that they have a bad configuration.
Proposal
In the geo check script during the database replication setup for Geo, include a check to make sure that the Praefect database is not on the same server as the PG database being replicated