[ML] improve discoverability on dashboard-embeddable ML anomalies

[ghudgins]

Describe the feature: Today it is difficult for a user to discover how to embed ML anomalies on a dashboard.

Quick brainstorm of ideas to solve this:

• add "add to dashboard" action to Single Metric Viewer
• add "add to dashboard" action to Actions under each anomaly

Describe a specific use case for the feature: Today: A skilled user, having seen a webinar where a dashboard contained ML anomaly embeddable, was unable to find the feature when searching the ML app.

Desired: Finding dashboard actions in a consistent place.

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[darnautov]

Hi @ghudgins. Single Metric Viewer and Anomalies Table are not embeddables (yet). At the moment it's possible to embed Anomaly Swim lane and Anomalies charts.