Improve CheckUpdateModel

v2rayN/ServiceLib/Manager/AppManager.cs

@@ -48,6 +48,13 @@ public sealed class AppManager
         }
     }
 
+    public Dictionary<ECoreType, string> LastCheckUpdateResults { get; set; } = new();
+
+    public void SetLastCheckUpdateResult(ECoreType coreType, string result)
+    {
+        LastCheckUpdateResults[coreType] = result;
+    }
+
     #endregion Property
 
     #region App