KIP-244 — Add Record Header support to Kafka Streams Processor API

Accepted Kafka 2.0 Streams

Adds Headers access to the Kafka Streams Processor API via ProcessorContext#headers() and exposes headers in ConsumerRecordFactory and OutputVerifier for testing, enabling processors to read, write, and propagate record headers. Headers were available in the producer and consumer APIs but inaccessible in Streams, blocking use cases like distributed tracing context propagation through stream topologies.

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