[ML] Add action for adding log pattern / log rate analysis embeddables to a dashboard or case.

[peteharverson]

Log pattern analysis results can be added to a dashboard from the 'Add panel' flyout within Dashboard. However it is not currently possible to add the results to a new or existing dashboard / case from within the ML AIOps page. An action should be added to the Log pattern analysis page, in a similar approach to that which is used for the anomaly detection and change point detection panels.

The action should also be added for log rate analysis once that new embeddable is available (see #197943).

[elasticmachine]

Pinging @elastic/ml-ui (:ml)