<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#37503
Test-code changes only. No product changes.
Adding Windows SCEP support for osquery and Windows integration tests.
Refactoring so that code can be reused from Apple client.
Can be used when working on
https://github.com/fleetdm/fleet/issues/45550
# Checklist for submitter
## Testing
- [x] Added/updated automated tests
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Improved Windows MDM SCEP certificate installation handling during
profile enrollment (avoids duplicate responses and properly tracks
handled commands).
* **Monitoring & Observability**
* Added SCEP enrollment metrics: requests, successes, and errors.
* **Tests**
* Expanded unit and integration tests for Windows SCEP parsing,
enrollment flows, and end-to-end profile verification.
* **Refactor**
* Centralized SCEP exchange logic for Apple and Windows test flows.
<!-- review_stack_entry_start -->
[](https://app.coderabbit.ai/change-stack/fleetdm/fleet/pull/44562?utm_source=github_walkthrough&utm_medium=github&utm_campaign=change_stack)
<!-- review_stack_entry_end -->
<!-- end of auto-generated comment: release notes by coderabbit.ai -->