• [Feature] Introduce transactions support.
• [Improvement] Expand LoggerListener to inform about transactions (info level).
• [Improvement] Allow waterdrop to use topic as a symbol or a string.
• [Improvement] Enhance both message.acknowledged and error.occurred (for librdkafka.dispatch_error) with full delivery_report.
• [Improvement] Provide #close! that will force producer close even with outgoing data after the ma wait timeout.
• [Improvement] Provide #purge that will purge any outgoing data and data from the internal queues (both WaterDrop and librdkafka).
• [Fix] Fix the librdkafka.dispatch_error error dispatch for errors with negative code.