Self-organizing hash table to improve the performance of bucket aggregations (opensearch-project#7652)

* Add self-organizing hash table to improve the performance of bucket aggregations

Signed-off-by: Ketan Verma <ketan9495@gmail.com>

* Updated approach: PSL, fingerprint and recency information are embedded in the hash table itself

Signed-off-by: Ketan Verma <ketan9495@gmail.com>

* Updated tests and added microbenchmarks

Signed-off-by: Ketan Verma <ketan9495@gmail.com>

* Renamed FastLongHash to ReorganizingLongHash and updated the default initial capacity

Signed-off-by: Ketan Verma <ketan9495@gmail.com>

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Signed-off-by: Ketan Verma <ketan9495@gmail.com>

Author: ketanv3

CHANGELOG.md

@@ -136,6 +136,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Compress and cache cluster state during validate join request ([#7321](https://github.com/opensearch-project/OpenSearch/pull/7321))
 - [Snapshot Interop] Add Changes in Create Snapshot Flow for remote store interoperability. ([#7118](https://github.com/opensearch-project/OpenSearch/pull/7118))
 - Allow insecure string settings to warn-log usage and advise to migration of a newer secure variant ([#5496](https://github.com/opensearch-project/OpenSearch/pull/5496))
+- Add self-organizing hash table to improve the performance of bucket aggregations ([#7652](https://github.com/opensearch-project/OpenSearch/pull/7652))
 
 ### Deprecated