Expose the simulation-time object IDs

They are useful

GamecraftModdingAPI/Blocks/BlockEngine.cs

@@ -144,14 +144,14 @@ namespace GamecraftModdingAPI.Blocks
 			return ret.ToArray();
 		}
 
-		public ObjectIdentifier[] GetObjectIDsFromID(byte id)
+		public ObjectIdentifier[] GetObjectIDsFromID(byte id, bool sim)
 		{
 			var ret = new FasterList<ObjectIdentifier>(4);
 			if (!entitiesDB.HasAny<ObjectIdEntityStruct>(CommonExclusiveGroups.OWNED_BLOCKS_GROUP))
 				return new ObjectIdentifier[0];
 			var oids = entitiesDB.QueryEntities<ObjectIdEntityStruct>(CommonExclusiveGroups.OWNED_BLOCKS_GROUP);
 			foreach (ref ObjectIdEntityStruct oid in oids)
-				if (oid.objectId == id)
+				if (sim ? oid.simObjectId == id : oid.objectId == id)
 					ret.Add(new ObjectIdentifier(oid.ID));
 			return ret.ToArray();
 		}

GamecraftModdingAPI/Blocks/ObjectIdentifier.cs

@@ -32,10 +32,25 @@ namespace GamecraftModdingAPI.Blocks
         }
 
         /// <summary>
-        /// Finds the identfier blocks with the given ID.
+        /// Simulation-time ID. Assigned by the game starting from 0.
+        /// </summary>
+        public byte SimID
+        {
+            get => BlockEngine.GetBlockInfo<ObjectIdEntityStruct>(Id).simObjectId;
+        }
+
+        /// <summary>
+        /// Finds the identifier blocks with the given ID.
         /// </summary>
         /// <param name="id">The ID to look for</param>
         /// <returns>An array that may be empty</returns>
-        public static ObjectIdentifier[] GetByID(char id) => BlockEngine.GetObjectIDsFromID((byte) (id - 'A'));
+        public static ObjectIdentifier[] GetByID(char id) => BlockEngine.GetObjectIDsFromID((byte) (id - 'A'), false);
+        
+        /// <summary>
+        /// Finds the identifier blocks with the given simulation-time ID. This ID is assigned by the game starting from 0.
+        /// </summary>
+        /// <param name="id"></param>
+        /// <returns></returns>
+        public static ObjectIdentifier[] GetBySimID(byte id) => BlockEngine.GetObjectIDsFromID(id, true);
     }
 }