Add logic for import of combination from xls files

StructureHelperCommon/Models/Forces/ColumnedFileProperty.cs

@@ -0,0 +1,45 @@
+using StructureHelperCommon.Infrastructures.Enums;
+using StructureHelperCommon.Infrastructures.Interfaces;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperCommon.Models.Forces
+{
+    /// <inheritdoc/>
+    public class ColumnedFileProperty : IColumnedFileProperty
+    {
+        private IUpdateStrategy<IColumnedFileProperty> updateStrategy;
+        /// <inheritdoc/>
+        public Guid Id { get; private set; }
+        /// <inheritdoc/>
+        public string FilePath { get; set; } = string.Empty;
+        /// <inheritdoc/>
+        public int SkipRowBeforeHeaderCount { get; set; } = 2;
+        /// <inheritdoc/>
+        public int SkipRowHeaderCount { get; set; } = 1;
+        /// <inheritdoc/>
+        public double GlobalFactor { get; set; } = 1d;
+        /// <inheritdoc/>
+        public List<IColumnProperty> ColumnProperties { get; } = new();
+
+        public ColumnedFileProperty(Guid id)
+        {
+            Id = id;
+        }
+        public ColumnedFileProperty() : this (Guid.NewGuid())
+        {
+            
+        }
+
+        public object Clone()
+        {
+            updateStrategy ??= new ColumnedFilePropertyUpdateStrategy();
+            ColumnedFileProperty newItem = new();
+            updateStrategy.Update(newItem, this);
+            return newItem;
+        }
+    }
+}