[DOCS] Cases in Stack Management

[lcawl]

Relates to #125224 and #125479

Milestone 1:

• Add Cases introductory content to the Kibana Guide. Re-use existing content from Observability Guide and Security Guide: [DOCS] Add Stack Management cases #126960

Milestone 2:

• Add configuration details for external connectors. Re-use existing content from Observability Guide and Security Guide, as appropriate: [DOCS] Add Cases connector details #127232
• Add Lens visualization details, per Security Guide: [DOCS] Add Stack Management cases #126960

Milestone 3:

• Globalize the attributes that are used by the cases APIs in the Security Guide: Add shared third-party connectors docs#2395
• Add Cases API landing page in Kibana Guide: [DOCS] Add Cases API links #127647
• Copy cases API pages into Kibana Guide from Security Guide, generalizing where necessary:
  • Create case: [DOCS] Add create case and update case APIs #127936
  • Add comment [DOCS] Case comment APIs #128443
  • Update case : [DOCS] Add create case and update case APIs #127936
  • Update comment [DOCS] Case comment APIs #128443
  • Find cases: [DOCS] Add find case APIs #127686
  • Get case: [DOCS] Adds GET case API docs #128606
  • Get all case comments [DOCS] Add get case comments API #128694
  • Get comment [DOCS] Add get case comments API #128694
  • Get all case activity: [DOCS] Adds GET case activity and GET tags API docs #128874
  • Get tags: [DOCS] Adds GET case activity and GET tags API docs #128874
  • Get reporters: [DOCS] Adds GET reporters to cases API docs #129089
  • Get status: [DOCS] Get case status API #128802
  • Delete comment: [DOCS] Delete cases and comments APIs #128329
  • Delete all comments: [DOCS] Delete cases and comments APIs #128329
  • Delete case: [DOCS] Delete cases and comments APIs #128329
  • Set default Elastic Security UI connector (remove security-specific details): [DOCS] Set, get, update case configuration #129271
  • Update case configurations [DOCS] Set, get, update case configuration #129271
  • Get current connector: [DOCS] Set, get, update case configuration #129271
  • Find connectors: [DOCS] Add find case APIs #127686
  • Push case - [DOCS] Add final case APIs #130161
  • Find cases by alert (Change "find" to "get"?) - [DOCS] Add final case APIs #130161
  • Find all alerts attached to a case (ditto) - [DOCS] Add final case APIs #130161

Milestone 4:

• (Optional) Remove duplicated API pages from Security Guide, link to Kibana Guide instead: https://github.com/elastic/website-development/issues/9202, [DOCS] Remove redundant case API docs security-docs#1856
• Optionally link to this documentation from within the Stack Management > Cases app.
• Determine whether any additional tooltips or popovers are required.

[elasticmachine]

Pinging @elastic/kibana-docs (Team:Docs)

[elasticmachine]

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