[Request] add userSearchBase and groupSearchBase to security/RBAC config

As an additional hint for MDS / Confluent Server Authorizer's LDAP configuration, add the following parameters with their defaults (to keep same functionality within current examples):

- `userSearchScope: 1`
- `groupSearchScope: 1`

These configuration should go into `services.mds.provider.ldap.configurations` section ([here](https://github.com/confluentinc/confluent-kubernetes-examples/blob/e73a056f780bc8e48b86fe7cf79a77447694bee3/security/production-secure-deploy/confluent-platform-production.yaml#L77-L86)).

The user may continue to refer to the [LDAP Authorizer documentation](https://docs.confluent.io/platform/current/security/ldap-authorizer/configuration.html#ldap-auth-configuration-options) for clarification on these properties.