KIP-444 — Augment metrics for Kafka Streams

Accepted Kafka 2.4 StreamsMetrics

Adds extensive Kafka Streams JMX metrics covering thread state, task counts (active, standby, restored), store sizes, record processing rates, commit rates, and punctuator invocation rates. The existing Streams metrics were too sparse to support production monitoring dashboards, alerting thresholds, or autoscaling decisions based on processing lag.

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