[7.11] [Security Solution] Fix Timeline event details layout (#88377)

[patrykkopycinski]

Backports the following commits to 7.11:

• [Security Solution] Fix Timeline event details layout ([Security Solution] Fix Timeline event details layout #88377)

[kibanamachine]

💛 Build succeeded, but was flaky

• continuous-integration/kibana-ci/pull-request
• Commit: 947b675
• Flaky suites:
  • xpack-securitySolutionCypress

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Test Failures

Creates a timeline.Timelines Creates a timeline

Link to Jenkins

Stack Trace

Failed Tests Reporter:
  - Test has failed 19 times on tracked branches: https://github.com/elastic/kibana/issues/79389

AssertionError: Timed out retrying after 60000ms: Expected to find element: `[data-test-subj="description"]`, but never found it.
    at Context.eval (http://localhost:6111/__cypress/tests?p=cypress/integration/timeline_creation.spec.ts:15055:16)

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Metrics [docs]

Async chunks

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

id	before	after	diff
securitySolution	8.5MB	8.5MB	+26.0B
triggersActionsUi	1.5MB	1.5MB	-26.9KB
total			-26.9KB

Page load bundle

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

id	before	after	diff
triggersActionsUi	162.1KB	162.2KB	+102.0B

Unknown metric groups

async chunk count

id	before	after	diff
triggersActionsUi	31	32	+1

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@elasticmachine merge upstream