For #30947
# Checklist for submitter
- [x] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements)
- [x] Added/updated automated tests
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added support for requiring HTTP message signatures for fleetd
requests, configurable via a new setting.
* Enhanced middleware to enforce HTTP message signature requirements
when enabled.
* **Tests**
* Introduced integration tests to verify host identity endpoints enforce
HTTP message signature requirements.
* Updated test utilities and suite setup to support configurable
signature enforcement.
* **Chores**
* Refactored configuration and test server options to support the new
signature enforcement feature.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Victor Lyuboslavsky
f79fed9712