[UI/Core Split] Refactor GetPortMappingsFromServerConfig in Utilities

[benfleuty]

The GetPortMappingsFromServerConfig method in Utilities.cs retrieves port mapping information from the server configuration. Accessing and processing server configuration is a core responsibility.

This logic should reside within a service or class specifically responsible for managing and accessing server configuration data in the core layer.

Action:

1. Create or identify a core-level class responsible for managing server configuration (e.g., ServerConfigurationService.cs).
2. Move the GetPortMappingsFromServerConfig method to this class.
3. Update any code that uses GetPortMappingsFromServerConfig to reference the new service.
4. Add or update tests for the port mapping retrieval logic.