Add import primitives to cross-section

StructureHelperLogics/NdmCalculations/Primitives/Logics/IGetPrimitivesLogic.cs

@@ -0,0 +1,14 @@
+using StructureHelperCommon.Services.Exports;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperLogics.NdmCalculations.Primitives
+{
+    public interface IGetPrimitivesLogic : IImportLogic
+    {
+        List<INdmPrimitive> Primitives { get; }
+    }
+}