Moved from SourceTask#commit() to SourceTask#commitRecord()

[limitium]

Solution that fixes #75

[Nephery]

Hi, thank you for your contribution.

Instead of using BytesXMLMessage.getAckMessageId(), it would be better to use BytesXMLMessage.getReplicationGroupMessageId() instead.

Also, could you write a test for this scenario?

[limitium]

Hey, thanks for the comment.
There're couple of changes for now

1. No reason to use any IDs since message is still in heap, so removed auxiliary map and simplified that part
2. Noticed huge performance degradation in 3 orders of magnitude, because of internal solace client buffer for acks and another pattern how #commitRecrod() is called. Have to implement similar buffer at task level in terms of capacity and flushing. Now performance at the same level.

Haven't find how to cover this with test. However here is a link for how kafka-connect calls commits

committableRecords.forEach(this::commitTaskRecord);