Wait for batch size to be reached before processing

[adriaandotcom]

Feature request
It would be great to have a feature that allows for waiting until a specified batch size is reached before processing a batch of jobs. This would enable more efficient batch processing and help improve performance.

Use Case
In our case, we use the Elasticsearch bulk API to ingest data. The performance difference between ingesting 50 documents at once versus processing them individually is significant. Waiting for 50 jobs to accumulate before triggering the batch in BullMQ would vastly improve our workload efficiency and reduce processing overhead.

Proposed Solution

• Add a configurable option to delay batch processing until the batch size limit is reached.
• Optionally, include a timeout so the batch is processed after a certain time even if the batch size is not fully reached.

This feature would make BullMQ an even better fit for use cases involving bulk processing, like ours.