Add alerts to case in bulk

[yagely80]

Describe the feature:
As a soc analyst, sometimes i need to add a large amount of alerts to a case at once , which i cant to in the current version.
Describe a specific use case for the feature:
A lot of alerts are trigerring at once, and they all need to go into a certian case for a follow-up

[elasticmachine]

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

[elasticmachine]

Pinging @elastic/response-ops-cases (Feature:Cases)

[cnasikas]

Hi @yagely80! Thank you for your feedback. We added this feature in 8.3 in this PR #128875. I am closing the issue as it is already implemented. Let me know if have in mind a different user flow. Also, could you please tell me how many alerts you want to add in a case? This will help us to understand your use cases if in the future we want to provide an automated way to attach alerts to a case.