Add function trace

StructureHelperCommon/Infrastructures/Interfaces/FunctionDecorator.cs

@@ -52,5 +52,9 @@ namespace StructureHelperCommon.Infrastructures.Interfaces
         {
             return function.GetGraphSettings();
         }
+        public virtual string GetTrace()
+        {
+            return function.GetTrace();
+        }
     }
 }

StructureHelperCommon/Infrastructures/Interfaces/IOneVariableFunction.cs

@@ -30,5 +30,6 @@ namespace StructureHelperCommon.Infrastructures.Interfaces
         public bool Check();
         public double GetByX(double xValue);
         public GraphSettings GetGraphSettings();
+        public string GetTrace();
     }
 }