kafka-indexing: Report consumer io time

[ac9817]

Description

This PR adds the visibility into the io time spent by the kafka consumer during the index task. This helps us see if there is any correlation between this versus the future lag and could make changes to autoscaler strategies.

Also, adds datasource dimension to it to differentiate cases where both supervisors uses same topic.

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Key changed/added classes in this PR

• KafkaConsumerMonitor.java

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This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.