Add check for Menu Router (Check for potentially malicious entries in the menu router)

Problem/Motivation

Drupal FIT currently does not detect suspicious or unsafe routes in the menu/router system, which can allow malicious or misconfigured entries to expose admin paths or execute insecure callbacks without proper access control.

Steps to reproduce

Proposed resolution

Add a new Security FitCheck plugin MenuRouterMaliciousEntryCheck that:

• Scans all routes/menu entries for unsafe patterns, such as admin-style paths exposed to non-admin roles or routes without proper access checks.
• Flags any potentially malicious or misconfigured entries with a default FitWeight::High, and escalates to FitWeight::Critical when an exposed route grants access to clearly sensitive/admin functionality.
• Reports the affected routes in the FitResult so site owners can review, tighten access, or remove the problematic entries.

Remaining tasks

User interface changes

API changes

Data model changes