[Internal]: Improve alert muting and bulk muting in O11y solution

[tiamliu]

Description

What: improving alert muting feature and support bulk muting in O11y solution
When: 9.3
Why: making muting feature more user friendly and helping reduce alert noises during active investigation.

Resources

github issue: https://github.com/elastic/rna-program/issues/42

Which documentation set does this change impact?

Elastic On-Prem and Cloud (all)

Feature differences

the feature is identical in all deployment types

What release is this request related to?

N/A

Serverless release

9.3

Collaboration model

The documentation team

Point of contact.

Main contact: @maryam-saeidi @dominiqueclarke @cnasikas

Stakeholders: @drewpost @tiamliu @jasonrhodes