[AO] Add threshold information to the metric threshold alert details page

[maryam-saeidi]

Closes #153740, closes #153833, closes #155593

This PR adds threshold information and rule name to the metric threshold alert details page.

🧪 How to test

• Add xpack.observability.unsafe.alertDetails.metrics.enabled: true to the Kibana config
• Create a metric threshold rule with multiple conditions that generates an alert
• Go to the alert details page and check threshold information
• Click on the rule link; it should send you to the rule page

[apmmachine]

🤖 GitHub comments

Expand to view the GitHub comments

Just comment with:

• /oblt-deploy : Deploy a Kibana instance using the Observability test environments.
• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[elasticmachine]

Pinging @elastic/actionable-observability (Team: Actionable Observability)

[CoenWarmer]

LGTM!

[mohamedhamed-ahmed]

minor comments, LGTM !

[mohamedhamed-ahmed]

nit: maybe extracting this would make it easier to read?

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: 7d517f5

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
infra	1356	1357	+1

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
infra	2.0MB	2.0MB	+2.6KB
observability	1.1MB	1.1MB	+66.0B
total			+2.6KB

Unknown metric groups

ESLint disabled line counts

id	before	after	diff
enterpriseSearch	17	19	+2
securitySolution	396	399	+3
total			+5

Total ESLint disabled count

id	before	after	diff
enterpriseSearch	18	20	+2
securitySolution	476	479	+3
total			+5

History

• 💚 Build #122347 succeeded 0c6439c
• 💚 Build #122069 succeeded 1a6ed47
• 💚 Build #122068 succeeded cebda3f
• 💚 Build #121923 succeeded 4eea41f

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @maryam-saeidi