Neo4j Auto-Insert to OpenSearch

[fbaig]

It will be ideal if Neo4j pushes to OpenSearch directly instead of current working i.e.
(1) insert to Neo4j
(2) insert to OpenSearch in the endpoint.

[YunfanKang]

Seems there are more duplications showing up from the search result. Implementing the ranking would also benefit from this seperation so that I would recommend we we resolve this before working on the database-related sorting and ranking.