KIP-470 — TopologyTestDriver test input and output usability improvements

Discussion Kafka 2.4 StreamsTesting

Introduces strongly-typed `TestInputTopic<K,V>` and `TestOutputTopic<K,V>` wrappers for `TopologyTestDriver` with fluent pipe/read methods, deprecating the raw `ConsumerRecordFactory` and `pipeInput`/`readOutput` APIs. Existing `TopologyTestDriver` tests require verbose boilerplate—constructing `ConsumerRecord` objects manually and passing deserializers on every read—making topology tests significantly larger than the application code under test.

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