[7.x] [Fleet] Update agent details page (#84434)

[nchaulet]

Backports the following commits to 7.x:

• [Fleet] Update agent details page ([Fleet] Update agent details page  #84434)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 1892204

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
fleet	446	449	+3

Async chunks

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

id	before	after	diff
fleet	1.1MB	1.1MB	+7.8KB

Page load bundle

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

id	before	after	diff
fleet	374.8KB	374.9KB	+62.0B

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream