Added _search with sort: direction.

[dblock]

Description

• Added _search with sort: direction.
• Added a test for search_after.

Issues Resolved

Closes #173.

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[github-actions]

Changes Analysis

Commit SHA: b5d8a2c
Comparing To SHA: d170916

API Changes

Summary

└─┬Components
  ├──[➕] schemas (31088:7)
  └─┬_common___SortCombinations
    ├──[➕] oneOf (32506:7)
    └─┬ONEOF
      └──[🔀] $ref (31088:13)❌ 

Document Element	Total Changes	Breaking Changes
components	3	1

• ❌ BREAKING Changes: 1 out of 3
• Modifications: 1
• Additions: 2
• Breaking Modifications: 1

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/11726837940/artifacts/2158683531

API Coverage

	Before	After	Δ
Covered (%)	588 (57.59 %)	588 (57.59 %)	0 (0 %)
Uncovered (%)	433 (42.41 %)	433 (42.41 %)	0 (0 %)
Unknown	35	35	0

[github-actions]

Spec Test Coverage Analysis

Total	Tested
510	315 (61.76 %)