[ML] Prompt the user to delete alerting rules while deleting anomaly detection jobs

[darnautov]

Currently, when a user deletes an anomaly detection job used in alerting rules, it causes errors due to these rules referencing the deleted job. To mitigate this issue, we should prompt users to delete associated alerting rules, similar to the functionality of the "Delete annotations" toggle.

Note that the user can still delete a job with the Elasticsearch API call.

[elasticmachine]

Pinging @elastic/ml-ui (:ml)