Add calculators saving

StructureHelperCommon/Models/Calculators/Accuracy.cs

@@ -1,8 +1,25 @@
-namespace StructureHelperCommon.Models.Calculators
+using System;
+
+namespace StructureHelperCommon.Models.Calculators
 {
+    /// <inheritdoc/>
     public class Accuracy : IAccuracy
     {
+        /// <inheritdoc/>
+        public Guid Id { get; }
+        /// <inheritdoc/>
         public double IterationAccuracy { get; set; }
+        /// <inheritdoc/>
         public int MaxIterationCount { get; set; }
+        public Accuracy(Guid id)
+        {
+            Id = id;
+        }
+
+        public Accuracy() : this (Guid.NewGuid())
+        {
+            
+        }
+
     }
 }