[Cases] User assignment enhancements

[cnasikas]

In #140208 we introduced the ability to assign users to a case. This issue describes various enhancements that can become to improve UX and testing. Specifically:

• Disable queries before opening the popover (use react query enabled feature)
• Filter unassigned cases ([Cases] Add the ability to filter for cases without assignees #143390)
• Check if we have unit tests
  • x-pack/plugins/cases/public/components/all_cases/all_cases_list.tsx
  • x-pack/plugins/cases/public/components/all_cases/columns.tsx
  • x-pack/plugins/cases/public/components/all_cases/index.test.tsx
  • x-pack/plugins/cases/public/components/case_view/case_view_page.test.tsx
  • x-pack/plugins/cases/public/components/case_view/components/case_view_activity.test.tsx
  • x-pack/plugins/cases/public/components/case_view/components/sidebar_section.tsx
  • x-pack/plugins/cases/public/components/case_view/components/sidebar_title.tsx
  • x-pack/plugins/cases/public/components/user_profiles/unknown_user.tsx
• Hide the user assignment UX if security is disabled in Elasticsearch
• On the view cases page sort alpha without bringing to the top the current user ([Cases] Assignees enhancements #144836)
• On the assignee column the badges should be alpha ([Cases] Assignees enhancements #144836)
• Add 4px space between the avatars between assignee columns ([Cases] Assignees enhancements #144836)
• Suggestions ([Cases] Provide suggestions when searching for users #142310)
• E2e tests
  • Assigning users when creating a case ([Cases] Add e2e test for assigning users when creating a case #142939)
• Upgrade test ([Cases] Test assignees section on upgrade test #141973)
• Telemetry ([ResponseOps][Cases] Adding assignees telemetry #141168)
• Dismissable licensing callout
• Move the assigned users to the top of the list and organize them in alphabetical order in the popover
• Show the counter of total assignees when no users are assigned (i.e. “0 assignees”) ([Cases] Assignees enhancements #144836)
• Limit assignees on the UI ([UserProfiles] Add the ability to limit the number of users you can select #140889, [Cases] Assignees enhancements #144836)
• Use UserToolTip and UserAvatarTip from security. Reference: Added user avatar tooltip #142162 - @jonathan-buttner

[elasticmachine]

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

[elasticmachine]

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

[jonathan-buttner]

Use UserToolTip and UserAvatarTip from security.

I looked into this one a bit, looks like the sizing for the text and the avatar is different that what we use. Should we ask them to make it configurable?

Specifically:

• For the avatar they are using large -> https://github.com/elastic/kibana/blob/main/packages/kbn-user-profile-components/src/user_tooltip.tsx#L43 and we use medium -> https://github.com/elastic/kibana/blob/main/x-pack/plugins/cases/public/components/user_profiles/user_tooltip.tsx#L51
• For the text I'm not sure what it defaults to: https://github.com/elastic/kibana/blob/main/packages/kbn-user-profile-components/src/user_tooltip.tsx#L48 we use small: https://github.com/elastic/kibana/blob/main/x-pack/plugins/cases/public/components/user_profiles/user_tooltip.tsx#L21

[cnasikas]

I think it will be faster if we do the changes to the security component ourselves. They seem trivial.