refactor: simplify configuration handling for CMS URL

- Removed CmsServerBaseUrl utility class and updated references to directly access GwUrl from configuration.
- Adjusted frontoffice-deployment.yaml to remove CmsInternalBaseUrl environment variable.
- Updated appsettings for staging and main environments to reflect the correct CMS service URLs.
- Ensured consistent handling of GwUrl in TokenNotificationService and AddGrpcServices methods.

src/FrontOffice.Main/ConfigureServices.cs

@@ -100,9 +100,7 @@ public static class ConfigureServices
 
     public static IServiceCollection AddGrpcServices(this IServiceCollection services, IConfiguration configuration)
     {
-        var baseUrl = CmsServerBaseUrl.Resolve(configuration)
-            ?? throw new InvalidOperationException(
-                "GwUrl is required. Optionally set CmsInternalBaseUrl (e.g. http://cms-svc:8080 on Kubernetes) to bypass public TLS for server-side gRPC.");
+        var baseUrl = configuration["GwUrl"];
 
         // Register optimized HttpClient for gRPC
         services.AddScoped(sp =>