Currently, we send WriteWithoutShardKeyWithId in their own batch when ordered=false. This may cause an overall increase in latency due to several requests waiting to be processed serially as we increase the throughput of client requests, when compared to the performance with UpdateOneWithoutShardKeyWithId feature flag off.

Use existing retryable write client sessions to retry with idempotency in the case of stale shard/db version errors. This ticket is to fix it in batch_write_exec code path.