[ML] Increase coverage of a11y tests

[peteharverson]

Follow-up to #79352 to increase the accessibility test coverage of ML pages.

Anomaly detection

• [x] Multi-metric job wizard https://github.com/elastic/kibana/pull/142589
• [x] Population job wizard https://github.com/elastic/kibana/pull/146052
• [x] Advanced job wizard https://github.com/elastic/kibana/pull/146052
• [x] Categorization job wizard https://github.com/elastic/kibana/pull/162126
• [ ] Rare job wizard
• [x] Data recognizer job wizard https://github.com/elastic/kibana/pull/162126
• [ ] Edit job flyout
• [x] Forecast modal (Single Metric Viewer) https://github.com/elastic/kibana/pull/142589
• [ ] Edit rules flyout
• [ ] Model snapshot flyout

Data frame analytics

• [x] Create regression job https://github.com/elastic/kibana/pull/142589
• [x] Create classification job https://github.com/elastic/kibana/pull/142589
• [ ] Explore regression job
• [ ] Explore classification job
• [ ] Map view

Model management

• [ ] Trained models
• [ ] Nodes

File data visualizer

• [ ] Override settings flyout
• [ ] Import data advanced settings tab

Calendar settings

• [ ] Add event modal

AIOps

• [ ] Log Rate Analysis
• [ ] Log Pattern Analysis
• [ ] Change Point Detection

Stack Management

• [ ] Anomaly detection jobs list
• [ ] Data frame analytics jobs list
• [ ] Synchronize saved objects flyout

[elasticmachine]

Pinging @elastic/kibana-accessibility (Project:Accessibility)

[elasticmachine]

Pinging @elastic/ml-ui (:ml)