Store offset commit metadata when calling rd_kafka_offsets_store

[emasab]

See forked PR #4084

[milindl]

Carrying over approval, based on the older PR.
Might require some clang-format stuff it seems from the Semaphore run.

[emasab]

Thanks @mathispesch ! Haven't reviewed it yet, but let's wait a bit for merging this as we want to make the complete suite of regression tests to pass on master.

[mathispesch]

Hey @emasab,
Wondering if you had a chance to review this 🙂. Not so sure what's the status with the test suite as I can't see the check details.

[mathispesch]

Hey @emasab,
Could you give this a look? This branch now has several conflicts with master. I can help to resolve them.

[mathispesch]

I've merged master into https://github.com/mathispesch/librdkafka/tree/store-offsets-metadata. Regression tests pass locally.

[mathispesch]

Hey @emasab and @milindl,
Have you had a chance to look more into this? You should be able to rebase this on https://github.com/mathispesch/librdkafka/tree/store-offsets-metadata to resolve the conflicts with the base branch.

[emasab]

@mathispesch Sorry, this won't make it in this release because we want a release that contains KIP-320 asap. But will review it for next one.

[mathispesch]

Hey @emasab,
Is now a better time to give this one a look?

[mathispesch]

Thanks a lot!