feat(connector): Add read-only Opensearch connector

[elbinpallimalilibm]

Description

This PR adds a new read only connector for Opensearch

Motivation and Context

We had a need to run federated queries that also retrieved values from indices in Opensearch instances. This OpenSearch connector enables Presto to query OpenSearch indices using SQL syntax with support for vector similarity search via k-NN plugin and nested field access using dot notation.

Basic OpenSearch Index Querying

Query OpenSearch indices using standard SQL syntax:

SELECT _id, title, category, price
FROM opensearch.default.products
WHERE category = 'electronics' AND price > 100
ORDER BY price DESC
LIMIT 10;

Vector Search Table Function

Execute k-NN vector similarity searches directly in SQL using the table function syntax:

SELECT * FROM TABLE(opensearch.system.knn_search(
  index_name => 'documents',
  vector_field => 'embedding',
  query_vector => ARRAY[0.1, 0.2, 0.3],
  k => 10
)) ORDER BY _score DESC;

Nested Field Access with Dot Notation

Query nested JSON structures using dot notation without complex parsing:

SELECT id, user.name, user.profile.age, metadata.tags
FROM opensearch.default.users
WHERE user.profile.age > 25;

Impact

Test Plan

The unit tests include test classes extending AbstractTestQueries. So the full set of regression tests intended for connectors are run against this connector as well. Additional tests are included for the vector functions and individual classes.

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• Documented new properties (with its default value), SQL syntax, functions, or other functionality.
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• Adequate tests were added if applicable.
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Release Notes

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== RELEASE NOTES ==

General Changes
* Added new read only Opensearch connector.

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[elbinpallimalilibm]

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