[Enhancement] Optimize RocksDB ConsumeQueue iterator for sequential reads

### Before Creating the Enhancement Request

- [x] I have confirmed that this should be classified as an enhancement rather than a bug/feature.

### Summary

Currently, when RocketMQ uses RocksDB-based ConsumeQueue, the default read path is controlled by `iteratorWhenUseRocksdbConsumeQueue`, which is enabled by default.

However, this iterator is a RocketMQ-level reusable iterator. Internally, it still calls `RocksDBConsumeQueueTable#rangeQuery`, which builds N RocksDB keys for consecutive ConsumeQueue offsets and then calls `multiGet`.

This enhancement proposes optimizing the RocksDB ConsumeQueue sequential read path by using a bounded `RocksIterator` scan for consecutive offsets, while preserving the existing external ConsumeQueue iterator semantics.

### Motivation

Using RocksDB's native iterator scan for continuous offsets to improve performance.

### Describe the Solution You'd Like

Use a bounded RocksIterator scan in RocksDBConsumeQueueTable#rangeQuery to read continuous offsets while keeping existing ConsumeQueue iterator semantics unchanged.

### Describe Alternatives You've Considered

No

### Additional Context

_No response_

Start by reading RocksDBConsumeQueueTable#rangeQuery and tracing the iteratorWhenUseRocksdbConsumeQueue read path. Compare the existing multiGet behavior with a bounded RocksIterator scan for consecutive offsets, then verify that the external ConsumeQueue iterator semantics remain unchanged.

Written by the indexing model from the issue text.