HAKAN'S REQUIREMENT - Refactor API base URL configuration structure

Replaced ApiBaseUrl and DataApiBaseUrl with BaseUrl, ApiDefaultUrl, and service-specific configuration sections (AuthService, UserManagerService, DbFirstService). Updated AppSettings and all code references to use the new structure. Revised logic for HTTP client base URL selection to prefer service-specific settings. Updated appsettings files and added an example configuration for clarity and maintainability.

DbFirst.API/Dashboards/DashboardConfiguratorFactory.cs

@@ -28,7 +28,7 @@ public static class DashboardConfiguratorFactory
         }
 
         var dashboardBaseUrl = configuration["Dashboard:BaseUrl"]
-            ?? configuration["ApiBaseUrl"]
+            ?? configuration["BaseUrl"]
             ?? configuration["ASPNETCORE_URLS"]?.Split(';', StringSplitOptions.RemoveEmptyEntries).FirstOrDefault()
             ?? "https://localhost:7204";