Skip control records without auto-resolve

[tulios]

This PR solves issue #403.

It does two things:

1. Automatically resolve the control record offset when resolving the last non-filtered offset of the batch
2. When the batch is an empty control batch, automatically resolve the offset

I wrote more on the code documentation; I will paste here for documentation purposes.

The transactional producer generates a control record after committing the transaction.
The control record is the last record on the RecordBatch, and it is filtered before it
reaches the eachBatch callback. When disabling auto-resolve, the user-land code won't
be able to resolve the control record offset, since it never reaches the callback,
causing stuck consumers as the consumer will never move the offset marker.

When the last offset of the batch is resolved, we should automatically resolve
the control record offset as this entry doesn't have any meaning to the user-land code,
and won't interfere with the stream processing.

I am pinging the people in the original issue since it's a bit old and you might miss this PR.
@kkurten @drojas @JaapRood @jasine @brandonl

[Nevon]

We talked about a potential way of testing this better, either by using the request instrumentation event to see how many fetches we make (might be flaky), or by setting the maxBytes low enough that you only ever get a single message in each batch, and then publishing a message after finishing the transaction. That way you should get "stuck" on the control batch without the fix.

[JaapRood]

Seems like a totally reasonable way to address this issue 👌👍

[tulios]

Pre-release 1.12.0-beta.0 published with the fix.