[APM] Alert annotations for the charts APM supports rules

[kpatticha]

Describe the feature:

In APM the user can create rules for:

• Latency
• Failed transaction rate
• Error count
• ML

afaik: We already show ML annotation

Describe a specific use case for the feature:

Show annotation in the charts when an alert is active and occurred in time similar:

[elasticmachine]

Pinging @elastic/obs-ux-infra_services-team (Team:obs-ux-infra_services)

[smith]

I already wrote this and @cauemarcondes deleted it haha #127658

Showing consistent annotations across different charts can be very valuable so we might want to think about how to come up with a more generic plan for expanding use of annotations in general, not just on a single chart.

[botelastic]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.