[ResponseOps] Initial deliverable for actionability of alerting

[chrisronline]

This is an actionable ticket off of this meta

For the initial deliverable, we should do the following:

• Decide upon which questions to answer initially: [Alerting] Phase 1 of AoA: First set of questions to answer #122362 (comment)
• Ensure we haver the proper plumbing to collect metrics to answer these questions: [ResponseOps] Add new plugin to collect additional kibana monitoring metrics #123241
• Implement the necessary metrics to answer these questions: [Alerting] Phase 2 of AoA: What metrics answer the first set of questions #122363
• Integrate with metric collection and ensure metrics are exposed through a public HTTP API [ResponseOps] Integrate rule and action monitoring data to the monitoring collection plugin #123416
• Determine how to visualize these appropriately in the Stack Monitoring UI: [Alerting] Phase 4 of AoA: Visualize and alert on available data  #122367
• Add docs: [RAM] Basic docs for alerting and stack monitoring integration #133304

With this deliverable, we will start collecting alerting performance metrics and exposing these through a publicly accessible HTTP api. We don't expect users to consume these yet, but it will be possible for support to add tooling to collect these metrics when bundling diagnostics.

[elasticmachine]

Pinging @elastic/response-ops (Team:ResponseOps)

[XavierM]

@lcawl I think I need your help on this #133304