Use batch-draining queues in SingleThreadExecutor

[merlimat]

Motivation

SingleThreadExecutor backs every OrderedExecutor thread — including the bookie read/write thread pools — so its queue is on the task-dispatch hot path. Today it uses:

• GrowableMpScArrayConsumerBlockingQueue (unbounded, the default), draining element-by-element via drainTo(ArrayList)
• JDK ArrayBlockingQueue (bounded, when maxTasksInQueue is set)

Meanwhile BatchedArrayBlockingQueue — purpose-built in the same package for the many-producers/one-consumer shape, with System.arraycopy batch draining — was unused by the executor. A JMH comparison (8 producers, consumers running the executor's exact drain loops) showed the growable queue is actually the slowest option, and the batched queue the fastest:

Queue	put throughput
GrowableMpScArrayConsumerBlockingQueue (current unbounded)	32.7 Mops/s
JDK ArrayBlockingQueue (current bounded)	43.3 Mops/s
GrowableBatchedArrayBlockingQueue (new, unbounded)	48.5 Mops/s (+48%)
BatchedArrayBlockingQueue (bounded)	51.4 Mops/s (+19%)

Changes

• Add GrowableBatchedArrayBlockingQueue: the unbounded companion of BatchedArrayBlockingQueue. Same single-lock design and two-span System.arraycopy batch operations (takeAll / pollAll / putAll), but with no notFull condition — producers never block; the backing array doubles when full (and never shrinks), like the queue it replaces.
• SingleThreadExecutor now uses BatchedArrayBlockingQueue for the bounded case and the new growable queue for the unbounded case, and the run loop drains with takeAll into a reusable Runnable[] (capped at 1024) instead of per-element drainTo(ArrayList).
• Remove GrowableMpScArrayConsumerBlockingQueue (and its test): the executor was its only production user, so it is fully superseded by the new queue. The stray usage in BatchedArrayBlockingQueueTest.blockingTake now tests BatchedArrayBlockingQueue itself, as intended.
• New unit test covering the growth paths (including growth and batch-insert with wrapped indexes) and the batched operations.
• New JMH benchmark (SingleThreadExecutorQueueBenchmark) comparing the queue options with executor-style consumers.

Verified: new queue test (9/9), BatchedArrayBlockingQueueTest, TestSingleThreadExecutor (10/10), TestOrderedExecutor, TestOrderedExecutorDecorators, plus BookieJournalTest as an integration smoke through the bookie path (16/16). Checkstyle clean.

[void-ptr974]

Maybe we need check initialcapacity non-negative here.