Remove ToList() method from PObjectStateHist class

The `ToList()` method in the `PObjectStateHist` class has been removed. This method previously returned a list of strings, including the `IntlState` property of `State1` and other state properties (`State2`, `State3`, `State4`). Its removal indicates that this functionality is no longer needed or has been refactored.

src/WorkFlow.Domain/Entities/PObjectStateHist.cs

@@ -64,9 +64,4 @@ public class PObjectStateHist
     public virtual State? State1 { get; set; }
 
     public virtual IEnumerable<PControlsTF>? TFControls { get; set; }
-
-    public IEnumerable<string?> ToList() => new List<string?>
-    {
-        State1?.IntlState, State2, State3, State4
-    };
 }