Upgrade dependency @opensearch-project/opensearch from 2.x to ^3.4.0 #839
Description
This major version release reworks the javascript API to be generated from the OpenSearch service definitions, rather than being all manually defined. As a result of this, some parameter names, etc, have changed, e.g., opType is now op_type or type, so they align with the actual API names rather than a javascript-conventional name. The code needs to be updated to reflect this. System tests fail, demonstrating the issues.