[ML] Increase Test Coverage 7.14

[walterra]

Follow up to #93205.

Meta issue to summarize improvements to test coverage for 7.14.

Jest unit tests

• Transform link to discover [ML] Transforms: Adds a link to discover from the transform list to the actions menu. #97805
• APM Correlations Unit Tests (WR) [ML] Fractions API fix and jest unit tests for APM Latency Correlations. #103907

API integration tests

part of #63700

• GET /data_frame/analytics/map/{id} (MA) [ML] Add api integration test for analytics map endpoint  #105531
• GET /api/ml/trained_models/{modelId?} (DA) [ML] Add integration tests for trained_models API  #104819
• GET /api/ml/trained_models/{modelId}/_stats (DA) [ML] Add integration tests for trained_models API  #104819
• GET /api/ml/trained_models/{modelId}/pipelines (DA) [ML] Add integration tests for trained_models API  #104819
• DELETE /api/ml/trained_models/{modelId} (DA) [ML] Add integration tests for trained_models API  #104819
• POST /api/ml/indices/field_caps {JG) [ML] Adding tests for ML's field caps endpoint #104315
• Enhanced saved object sync [ML] Improvements to job saved object sync #101899 (JG)
• APM Correlations Search Strategy API Integration Tests (WR) [ML] API integration tests for APM latency correlation. #104644

Functional tests

• Transform link to discover [ML] Transforms: Adds a link to discover from the transform list to the actions menu. #97805
• Custom URLs (PH) [ML] Adds functional tests for anomaly detection job custom URLs #100455
• Data visualizer index pattern management (QN) [ML] Add index pattern management to index Data Visualizer #101316
• Anomaly Detection annotations (QN) [ML] Add functional tests for Anomaly Detection annotations #105527
• APM Correlations Functional Tests (WR) [ML] Fix custom index name settings, functional tests for APM Latency Correlation. #105200

Accessibility tests

part of #88496

[elasticmachine]

Pinging @elastic/ml-ui (:ml)