Feat: added a field for replication grants for roles

[Simon-Lind-glitch]

Add replication flag to PostgresUser

Adds a replication: true flag to the PostgresUser CRD. The use case is tools like Debezium that need a user with the replication attribute to manage logical slots and stream data using logical slots for CDC.

The implementation is cloud-provider aware. On standard Postgres, GCP and Azure it uses ALTER ROLE x WITH REPLICATION. On AWS RDS it grants rds_replication instead since RDS doesn't support ALTER ROLE for this attribute. See https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/PostgreSQL.Concepts.General.FeatureSupport.LogicalReplication.html

Example usage:

apiVersion: db.movetokube.com/v1alpha1
kind: PostgresUser
metadata:
name: debezium
spec:
role: debezium
database: my-db
secretName: debezium-secret
privileges: READ
replication: true

[Simon-Lind-glitch]

Maybe it should be called withReplication to more clearly reference the default way of assigning it to a role