propogate kwargs to cls in OpenSearchVectorSearch (#3416)
kwargs shoud be passed into cls so that opensearch client can be
properly initlized in __init__(). Otherwise logic like below will not
work. as auth will not be passed into __init__
```python
docsearch = OpenSearchVectorSearch.from_documents(docs, embeddings, opensearch_url="http://localhost:9200")
query = "What did the president say about Ketanji Brown Jackson"
docs = docsearch.similarity_search(query)
```
Co-authored-by: EC2 Default User <ec2-user@ip-172-31-28-97.ec2.internal>
