Add a PostgreSQL DB to our cluster

[IvanHristov98]

In order to have our application self contained we would have to have be able to deploy an internal PostgreSQL DB to be used by the server.

Note that the config should be added within separate yaml files in our chart folder, e.g. postgre-operator.yml, postgre-cr.yml

Acceptance criteria
💡 Learn about zalando postgre operator
💡 Add an operator deployment yaml to our config file
💡 Add a custom resource to our config file
💡 Make sure our deployment scripts are deploying the postgre

Note that deployment should be optional by specifying a flag