Migrate Search top anomalies to SDK using SDKRestClient

[dbwiddis]

Is your feature request related to a problem?

Part of opensearch-project/OpenSearch#5224

What solution would you like?

Migrate the Search top anomalies Rest API to Extensions SDK using SDKRestClient.

Use the implementation of #353 as a reference. Add new issues for any steps you skip.

Implement the following API endpoints:

• GET _plugins/_anomaly_detection/detectors/<detectorId>/results/_topAnomalies?historical=false
• GET _plugins/_anomaly_detection/detectors/<detectorId>/results/_topAnomalies?historical=true

[owaiskazi19]

Historical:

curl -X POST "localhost:9200/_extensions/_ad-extension/detectors/lxkMxYcBs8GyCDhBVHXy/results/_topAnomalies?historical=true&pretty" -H "Content-Type:application/json" --data '{"size":1,"category_field":["process"],"order":"severity","start_time_ms":1681775253000,"end_time_ms":1682596053000}'

Response:

{
  "buckets": [
    {
      "key": {
        "process": "process3"
      },
      "doc_count": 6,
      "max_anomaly_grade": 0.8088288531976634
    },
    {
      "key": {
        "process": "process0"
      },
      "doc_count": 10,
      "max_anomaly_grade": 0.5819850963637767
    },
    {
      "key": {
        "process": "process2"
      },
      "doc_count": 8,
      "max_anomaly_grade": 0.5378144963535091
    }
  ]
}

HCAD:

curl -X GET "localhost:9200/_extensions/_ad-extension/detectors/3ZY_xYcBVyaRNun-bpWE/results/_topAnomalies?historical=false" -H "Content-Type:application/json" --data '{"size":3, "category_field": ["process"],"order":"severity","start_time_ms":1681732053000,"end_time_ms":1682642783000}'

Response:

{
  "buckets": [
    {
      "key": {
        "process": "process0"
      },
      "doc_count": 2,
      "max_anomaly_grade": 0.25124500247214804
    }
  ]
}