feat: Add dependency protocol checking and deletion checking for stream routing

[yixianOu]

Description

This PR implements dependency protocol checking and deletion protection for stream routes, resolving #6939.

Previously, it was possible to create a subordinate stream route referencing a non-existent superior_id or a superior route with a mismatched protocol. Additionally, superior routes could be deleted even while being referenced by subordinate routes, leading to potential runtime errors.

Checklist

• I have read the CONTRIBUTING guidelines.
• I have added tests to cover my changes.
• I have verified that the changes work as expected.

Changes

1. Dependency Checking: Added validation in check_conf to ensure that when a superior_id is provided:
   • The referenced superior route exists.
   • The protocol of the subordinate route matches the superior route.
2. Deletion Protection: Implemented a delete_checker to prevent the deletion of a stream route if it is currently referenced as a superior_id by other routes.
3. Tests: Added a new test file t/admin/stream-routes-subordinate.t covering various scenarios including creation, protocol mismatch, and deletion protection.

Related Issue

Resolves #6939

Sign-off

Signed-off-by: Orician 2018783812@qq.com