Rename the recordsProcessed field introduced in #15930

[ac9817]

Description

Following the rename suggested here: #15930 (comment)

The map structure for recordsProcessed is difficult for someone to understand without knowing the knowledge of partitions. Hence renamed it accordingly.

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Key changed/added classes in this PR

• IngestionStatsAndErrorsTaskReportData

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This PR has:

• been self-reviewed.
• 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.

[suneet-s]

I noticed the live reports for the supervisor that report offsets and lag do not mention perPartition in the key, so I thought recordsProcessed was more in-line with the existing naming scheme

https://github.com/apache/druid/blob/master/indexing-service/src/main/java/org/apache/druid/indexing/seekablestream/supervisor/TaskReportData.java#L32-L38

@kfaraz I do not have a strong opinion about this re-name. Up to you which key name you think is better.

[kfaraz]

Thanks for the clarification, @suneet-s .

Looking at the sample report, I realize that the word partition can be ambiguous too as it is often used to refer to segments. So we can just leave it as recordsProcessed.

@adithyachakilam , you may close this pull request for now.