…rules (elastic#225939)

## Summary

Addresses elastic#207172

Follow-up to: elastic#219628

Adds per-field badges to the rule details page so that users can see
which fields are modified on their customized prebuilt rules. Clicking
on the badges opens a rule diff flyout that displays more extensive
information.

Also switches the concurrency controls in the flyout to a static view in
which data doesn't change when it is stale, we just now display a
callout informing the user that the information they're viewing is
outdated.

### Screenshots

**Modified fields from the Rule Details page**
![Screenshot 2025-07-02 at 5 38
43 PM](https://github.com/user-attachments/assets/ae1d2865-f3bd-4d5b-a109-213f78ea194c)

**Flyout opened when those badges are clicked**
![Screenshot 2025-07-02 at 1 33
26 PM](https://github.com/user-attachments/assets/793371ae-7a7d-4b39-8889-d16bd7dff9ba)

### Checklist

Check the PR satisfies following conditions.

Reviewers should verify this PR satisfies this list as well.

- [x] 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
- [x] [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

(cherry picked from commit b261abb)

# Conflicts:
#	x-pack/solutions/security/plugins/security_solution/public/detection_engine/rule_details_ui/pages/rule_details/index.tsx