DevOps: migrate database to Postgres Operator

[pbastia]

AC

As a developer, I want to use the Postgres Operator database on the cluster, So I can use its latest features

ToDo

• Devise a migration process from the current spilo/patroni instance to the postgres operator
• Document said process thoroughly (it will be reused)
• Script said process, and test it as much as possible
• Execute the migration in the -dev environment

[pbastia]

@dleard @TimCsaky this is our working ticket, it was mentioned you were interested ;) we'll let you know when we start work on it

[pbastia]

Relevant RC thread about the PGUpgrade object and its caveats: https://chat.developer.gov.bc.ca/channel/crunchydb?msg=2efrDos2CjKaSFqJh