feat: Adding confluent cloud cluster entity

[dsankaraganti]

Relevant information

1. Adding new entity type for confluent cloud cluster
2. Changing the existing rule in ext-service type to not create service entity using confluent cloud open telemetry data

The entity type should going to be tested only in staging

Checklist

• [x] I've read the guidelines and understand the acceptance criteria.
• [x] The value of the attribute marked as identifier will be unique and valid.
• [x] I've confirmed that my entity type wasn't already defined. If it is I'm providing an explanation above.