Added signal shape name to the C# signal script interface

Author: Sharpe49

Source/Orts.Simulation/Simulation/Signalling/CsSignalScript.cs

@@ -2,6 +2,7 @@
 using ORTS.Scripting.Api;
 using System;
 using System.Collections.Generic;
+using System.IO;
 
 namespace Orts.Simulation.Signalling
 {
@@ -109,6 +110,10 @@ public enum BlockState
         /// </summary>
         public string SignalTypeName => SignalHead.SignalTypeName;
         /// <summary>
+        /// Name of the signal shape, as defined in sigcfg
+        /// </summary>
+        public string SignalShapeName => Path.GetFileNameWithoutExtension(SignalObject.WorldObject.SFileName);
+        /// <summary>
         /// Local storage of this signal, which can be accessed from other signals
         /// </summary>
         public Dictionary<int, int> SharedVariables => SignalObject.localStorage;