Default VM Database: OpenDJ --> Postgres

[nynymike]

LDAP is still a nice option for those developers who love ldif files and ldapsearch... but it's not a database supported anymore in production--replication in K8s is too fragile (replication is too fragile in general?) The default database for K8S has been MySQL for a while. For the VM, we decided to finally make Postgres the default database in Jans 1.0.23 and forward.

#7420