WIP: [AMQ-9484] Support exporting kahadb messages from a queue with an offset - Option B

[mattrpav]

[mattrpav]

One reason I thought iterating over the index was preferred vs seeking over the index was to skip over and not include any messages in the ackedAndPrepared collection.

    if (ackedAndPrepared != null && ackedAndPrepared.contains(entry.getValue().messageId)) {
        continue;
    }

[mattrpav]

Closing in favor of https://github.com/apache/activemq/pull/1208