migrated FunctionDefinitionNotFoundException to exceptions.cs

Author: Razmo99

src/PowerShellEditorServices/Services/PowerShell/Refactoring/Exceptions.cs

@@ -38,4 +38,21 @@ public TargetVariableIsDotSourcedException(string message, Exception inner)
         {
         }
     }
+
+    public class FunctionDefinitionNotFoundException : Exception
+    {
+        public FunctionDefinitionNotFoundException()
+        {
+        }
+
+        public FunctionDefinitionNotFoundException(string message)
+            : base(message)
+        {
+        }
+
+        public FunctionDefinitionNotFoundException(string message, Exception inner)
+            : base(message, inner)
+        {
+        }
+    }
 }