Separated merger and tester fixtures, fixed leftoever nulls.

[dblock]

Description

• Merger unit tests are using a spec from fixtures. This makes it a bit difficult to grok what's where when trying to add tests. I copied a spec from tester into merger fixtures.
• Fixes [BUG] merge for a specific version nullifies refs in an array #558.

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[github-actions]

Changes Analysis

Commit SHA: cf2ac23
Comparing To SHA: d279f4a

API Changes

Summary

└─┬Components
  ├─┬_common.mapping:XyShapeProperty
  │ └─┬Extensions
  │   └──[➕] x-version-added (36910:24)
  ├─┬_common:XyLocation
  │ └─┬Extensions
  │   └──[🔀] x-version-added (30258:24)
  ├─┬_common.mapping:XyPointProperty
  │ └─┬Extensions
  │   └──[➕] x-version-added (36892:24)
  └─┬_common.query_dsl:XyShapeQuery
    └─┬Extensions
      └──[🔀] x-version-added (38925:24)

Document Element	Total Changes	Breaking Changes
components	4	0

• Total Changes: 4
• Modifications: 2
• Additions: 2

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/10777177076/artifacts/1910038221

API Coverage

	Before	After	Δ
Covered (%)	537 (52.6 %)	537 (52.6 %)	0 (0 %)
Uncovered (%)	484 (47.4 %)	484 (47.4 %)	0 (0 %)
Unknown	26	26	0

[dblock]

@kolchfa-aws I re-added x-version-added: 2.4 for the types you've added in this PR here.

[github-actions]

Spec Test Coverage Analysis

Total	Tested
563	271 (48.13 %)