Fixing problem with zero term error texts

[cybearinsight]

I have change the limit on the error text to be limit on the call and actual length on the return. And I have updated the apl function to reflect that

I have left the Topic, Key and payload unchanged since we are using APL both and the producing and consuming end to handle the number of bytes, no matter it is text or binary.

[mkromberg]

Without any technical understanding of this, I still thought I would comment that I do not understand the comment about using APL at both ends. I don't think that will be the typical use case for a Kafka interface.

[cybearinsight]

We are not using zero termination on Topic, Key and Payload, the length is handle on APL with the shape and on the kafka side with a length field. But some of the error codes was handled as zero terminated and the length did not include the zero termination, so now I also return the length on the error messages from the C side to APL.

[martanit]

Line 8: you may want to add a 4↑ before Produce.