Description of problem:

The requirement is from the Citigroup from this slack channel: https://redhat-internal.slack.com/archives/C05DLMA6VBR/p1752759249073619

Related issue in Globalhub 1.6: https://issues.redhat.com/browse/ACM-23340

We are introduce the consumer group in the global hub CR: 

apiVersion: operator.open-cluster-management.io/v1alpha4
kind: MulticlusterGlobalHub
metadata:
  name: multiclusterglobalhub
  namespace: multicluster-global-hub
spec:
  availabilityConfig: Basic
  dataLayer:
    kafka:
      consumerGroupPrefix: org42_
      topics:
        specTopic: gh-spec
        statusTopic: gh-status.*
    postgres:
      retention: 18m
  enableMetrics: true
  installAgentOnLocal: true

ConsumerGroupPrefix specifies the prefix for Kafka consumer group IDs

The final consumer group ID is constructed as follows:

• For Global Hub: <prefix> + "global_hub"
• For Managed Hubs: <prefix> + <managed-hub-name> (hyphens replaced with underscores)
  If not specified, defaults to hub name only (hyphens replaced with underscores).

  Version-Release number of selected component (if applicable):

  How reproducible:

  Steps to Reproduce:

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Actual results:

Expected results:

Additional info: