[Tech Debt] Reorder Cases page

[CoenWarmer]

Resolves #152985

Summary

This PR updates the Cases Page to follow the newly agreed upon structure for the Observability app.

This PR is part of a larger effort to have all pages in the Observability app follow the same structure so they are more consistent with each other. More details in the epic: #152783

It also cleans up dead and unused components where found.

All design and functionality should be exactly the same as before.

Checklist

• Rename page component <to_name_of_page.tsx>
• Remove /container subfolder if available
• Try to inline translations in /translations.ts
• Try to move re-used components to /app_root/components/feature
• Try to move components that are only used in Page to /page/<name_of_page>/components/<component_name>.tsx

[kdelemme]

LGTM

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: f6fdd2e
• Storybooks Preview

Failed CI Steps

• FTR Configs #21

Test Failures

• [job] [logs] FTR Configs #21 / security APIs - Session Idle Session POST /internal/security/session should extend the session

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
observability	521	517	-4

Async chunks

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

id	before	after	diff
observability	1.1MB	1.1MB	-1.7KB

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
observability	88.5KB	88.4KB	-145.0B

Unknown metric groups

ESLint disabled line counts

id	before	after	diff
securitySolution	433	436	+3

Total ESLint disabled count

id	before	after	diff
securitySolution	513	516	+3

History

• 💔 Build #113822 failed c29996d
• 💔 Build #113815 failed 0dccf71
• 💔 Build #113810 failed 76aabd9
• 💔 Build #113803 failed 3a7e0ff
• 💔 Build #113800 failed 6165ef0

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