!2767 fix(#I56TZX ): update the Result to Close when return false in OnClosing callback

* fix: 修复关闭弹窗拦截后更正状态逻辑
* 修复OnClosing返回值不对的问题

src/BootstrapBlazor/Extensions/DialogServiceExtensions.cs

@@ -179,6 +179,10 @@ public static class DialogServiceExtensions
                 await option.Dialog.Close();
                 option.ReturnTask.SetResult(result);
             }
+            else
+            {
+                result = DialogResult.Close;
+            }
         };
 
         await service.Show(option, dialog);