Add vector search as new operation type to search

[VijayanB]

Description

For Vector search, we have to compare actual response's hits with expected neighbors to estimate recall for search. However, there is no provision to return recall similar to throughput. Hence, we will publish recall metrics like recall@k, recall@r as part of meta object. We also time those recall calculation and publish in ms to meta object.

Added tests to verify results are as expected.

Issues Resolved

Part of #103

Testing

• New functionality includes testing

[Describe how this change was tested]

make test 

.venv/lib/python3.8/site-packages/pkg_resources/__init__.py:2868
.venv/lib/python3.8/site-packages/pkg_resources/__init__.py:2868
  /Users/balasvij/PycharmProjects/knn/opensearch-benchmark/.venv/lib/python3.8/site-packages/pkg_resources/__init__.py:2868: DeprecationWarning: Deprecated call to `pkg_resources.declare_namespace('google')`.
  Implementing implicit namespace packages (as specified in PEP 420) is preferred to `pkg_resources.declare_namespace`. See https://setuptools.pypa.io/en/latest/references/keywords.html#keyword-namespace-packages
    declare_namespace(pkg)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
================= 1191 passed, 5 skipped, 3 warnings in 16.93s =================


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[VijayanB]

@jmazanec15 @navneet1v I removed recall@r, and, kept only recall@k, where, we will compare predictions with top k neighbors from neighbor's list.

[navneet1v]

@jmazanec15 @navneet1v I removed rcall@r, and, kept only recall@k, where, we will compare predictions with top k neighbors from neighbor's list.

can we have recall@1 always getting calculated?

[VijayanB]

@jmazanec15 @navneet1v I removed rcall@r, and, kept only recall@k, where, we will compare predictions with top k neighbors from neighbor's list.

can we have recall@1 always getting calculated?

Added recall@1 and updated testcase.

[IanHoang]

Left a couple comments