refactor: PostgresDatabase Collation Hint

[sislr]

      --location=nine-es34              Where the PostgreSQL database is created. Available locations are: nine-cz41, nine-cz42, nine-es34
      --postgres-database-version=17    Release version with which the PostgreSQL database is created. Available versions: 17
      --backup-schedule=daily           Backup schedule for the PostgreSQL database. Available schedules: disabled, daily
      --collation=C.UTF-8               Collation for the PostgreSQL database. Defaults to C.UTF-8.

C.UTF-8. looks a bit off IMO and hints above are also not ending with .