<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#37192
- Move /server/service/middleware/endpoint_utils to
/server/platform/endpointer
- Move /server/service/middleware/authzcheck to
/server/platform/middleware/authzcheck
- Move /server/service/middleware/ratelimit to
/server/platform/middleware/ratelimit
# Checklist for submitter
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
## Release Notes
* **Refactor**
* Reorganized internal endpoint utilities to a centralized platform
location for improved code organization and maintainability. No
functional changes to existing features or APIs.
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
