Refactor project files for improved readability and structure

- Cleaned up whitespace in Directory.Build.props and Directory.Packages.props for consistency.
- Reformatted project file references in PnvPanel.Api.csproj for better clarity.
- Enhanced code readability in various endpoint files by adjusting line breaks and indentation.
- Standardized method signatures and improved formatting in ResultExtensions and multiple endpoint classes for better maintainability.

backend/src/PnvPanel.Infrastructure/Identity/DbInitializerExtensions.cs

@@ -4,7 +4,10 @@ namespace PnvPanel.Infrastructure.Identity;
 
 public static class DbInitializerExtensions
 {
-    public static async Task SeedDataAsync(this IServiceProvider services, CancellationToken cancellationToken = default)
+    public static async Task SeedDataAsync(
+        this IServiceProvider services,
+        CancellationToken cancellationToken = default
+    )
     {
         await using var scope = services.CreateAsyncScope();
         var initializer = scope.ServiceProvider.GetRequiredService<DbInitializer>();