KIP-1325 — Add restore.buffered.records.per.partition to cap Kafka Streams state-restore memory

Accepted Kafka 4.5 Streams

Adds a restore.buffered.records.per.partition StreamsConfig that caps the per-partition restore buffer in StoreChangelogReader, pausing the restore consumer on partitions whose ChangelogMetadata buffer is full and resuming them once records have been applied to the state store. Kafka Streams enforces buffered.records.per.partition on the normal processing path but had no limit on the restore path, so large backfills could buffer changelog records unboundedly and trigger OutOfMemoryError.

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