[ML] Increase Test Coverage 8.4.0

[peteharverson]

Follow up to #130648.

Meta issue to summarize improvements to test coverage for 8.4.0.

API integration tests

• PUT /api/ml/anomaly_detectors/:jobId (job with datafeed) (JG)
  [ML] Fix put anomaly detection job endpoint when payload contains datafeed #134986
• GET /api/ml/filters/_stats (PH)
  [ML] Add API tests for filters stats endpoint #135118
• GET /api/ml/management/list/:listType (JG)
  [ML] Refactors management page to focus on space management tasks #134893
• POST /api/ml/validate/datafeed_preview (correct and incorrect time range) (JG)
  [ML] Use time range when validating datafeed preview #134073
• POST /internal/aiops/explain_log_rate_spikes(WR)
  [ML] Explain log rate spikes: Analysis API endpoint. #135058
  [ML] Explain log rate spikes: Adds API license check. #135431

Functional tests

• Creating ML jobs from Lens (JG)
  [ML] Anomaly detection job from lens functional tests #133899
• Transforms - num_failure_retries advanced setting
  [ML] Transforms: Adds per-transform setting for num_failure_retries to creation wizard and edit flyout and authorization info #135486
• Data visualizer filters (pinned filters) (QN)
  [ML] Increase Test Coverage 8.4.0  #133871
• Transform wizard show error/crashing when editting a cloned transform with filter aggregation (QN)
  [ML] Transforms: Fix unsupported boolean filter when cloning #137773
• Transform showing error toast messages in wizard when started (QN)
  [ML] Transforms: Fix data view error on cloning due to missing indices #138756
• Explain log rate spikes (WR/MA)
  [ML] Explain Log Rate Spikes: Basic functional tests. #138387
  [ML] Explain Log Rate Spikes: Extended Functional tests. #138661
• 3rd party models (DA)
  • Import models (RO)
    [ML] Functional tests - support tiny trained models #136010
  • Expanded row content of imported models (RO)
    [ML] Functional tests - support tiny trained models #136010
  • List
  • Start deployment (DA) [ML] Functional tests for 3rd party models deployment  #138242
  • Stop deployment (DA) [ML] Functional tests for 3rd party models deployment  #138242
  • Delete model (DA) [ML] Functional tests for deleting 3rd party models  #138425

[elasticmachine]

Pinging @elastic/ml-ui (:ml)