[Search] fix: FormattedMessage rendering escaped HTML instead of markup (#234079)

## Summary

After upgrading to [email protected], `<FormattedMessage>` no longer
renders raw HTML when returning strings from value formatters.
Previously, returning a string like `"<strong>...</strong>"` would be
interpreted as HTML and rendered. In v6, all strings are escaped for
safety, and only React elements are rendered as markup.

As a result, the `PagingInfoView` component which uses,
`<FormattedMessage>`, was displaying `<strong>` tags as plain text
instead of styled markup on the Docs Explorer page. This has been fixed
by updating the strong property in `<FormattedMessage>` to return a
React element.

**Before**

<img width="600" alt="Screenshot 2025-09-04 at 18 19 21"
src="https://github.com/user-attachments/assets/b0024691-753c-47ab-8d5c-92e9e06d96a6"
/>

**After**

<img width="600" alt="Screenshot 2025-09-04 at 18 27 04"
src="https://github.com/user-attachments/assets/63de1c5e-e129-4dd0-9f79-3537196c3a4c"
/>

### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [ ] ~Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/src/platform/packages/shared/kbn-i18n/README.md)~
- [ ]
~[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials~
- [ ] ~[Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios~
- [ ] ~If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list]~(https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [ ] ~This was checked for breaking HTTP API changes, and any breaking
changes have been approved by the breaking-change committee. The
`release_note:breaking` label should be applied in these situations.~
- [ ] ~[Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed~
- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)
- [x] Review the [backport
guidelines](https://docs.google.com/document/d/1VyN5k91e5OVumlc0Gb9RPa3h1ewuPE705nRtioPiTvY/edit?usp=sharing)
and apply applicable `backport:*` labels.

## Release note

Fixes the Docs Explorer paging info to correctly render bold text. After
upgrading to [email protected], the `<FormattedMessage>` component
escaped HTML returned from value formatters, causing `<strong>` tags to
appear as plain text. The component now uses React elements to render
the bold text properly.

Author: seialkali

x-pack/solutions/search/plugins/enterprise_search/public/applications/applications/components/search_application/docs_explorer/search_ui_components.tsx

@@ -171,8 +171,8 @@ export const PagingInfoView: React.FC<PagingInfoViewProps> = ({ start, end, tota
       values={{
         end,
         start,
+        strong: (chunks: React.ReactNode) => <strong>{chunks}</strong>,
         totalResults,
-        strong: (chunks) => `<strong>${chunks}</strong>`,
       }}
     />
   </EuiText>