[FEATURE] add batch_size parameter in text_embedding processor

[YeonghyeonKO]

Is your feature request related to a problem?

From OpenSearch 2.16, it's possible to add batch inference support in ingest processors which inherits from AbstractBatchingProcessor(opensearch-project/neural-search#820). From now on, OpenSearch java client doesn't support batch_size parameter(optional) when defining text_embedding processor.

What solution would you like?

• Add batch_size parameter in text_embedding processor which already exists.
• If the above action were merged, the next step would be including SparseEncodingProcessor in opensearch-java client.

[Xtansia]

@YeonghyeonKO your fix for this was released in v2.18.0 of the client