Specifying the behaviour of the ConsumerID field when configuring Kafka Pub/Sub

[KrylixZA]

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Description

This PR details the behaviour of configuration the ConsumerID field in the Apache Kafka Pub/Sub component. It all revolves around this code which basically ignores the ConsumerID field of the ConsumerGroup field is defined. This PR simply updates the field description table to show that a combination of the consumer group and a random unique identifier is used when defining the consumerId if the consumer group field is set.

Issue reference

Closes #3697