[ML] Anomaly Detection: Dashboard embeddable panels not announced correctly

[bhavyarm]

Description
When user clicks on add panel and then selects any of the ML embeddable panels (anomaly swim lane, single metric chart viewer, anomaly chart, change point detection), Kibana announces them as "Add panel" again without specific embeddable names and no focus. This doesn't give non-sighted user context about the add panel action they are trying to execute. If user clicks on tab again the keystroke lands somewhere else in dashboard.

Preconditions
Dashboards->Dashboard-> edit mode

Steps to reproduce

1. Navigate to Dashboards
2. Click a single dashboard open
3. Click edit
4. Run voiceover
5. Click on "Add Panel"
6. Click on any of the machine learning embeddables
7. Kibana announces the fly-out opening as "Add panel" without specifying which panel type the user is trying to add
8. Note the focus also doesn't land on the panel but elsewhere

Kibana Version: 8.18.0

OS: OS X

Browser: Chrome latest

WCAG or Vendor Guidance (optional)

• Understanding SC 4.1.2: Name, Role, Value (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/name-role-value.html)
• Understanding SC 2.4.3: Focus Order (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/focus-order.html)

Related to: https://github.com/elastic/kibana-team/issues/1559

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[elasticmachine]

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