Tests of crack calculator were added

StructureHelperCommon/Models/Calculators/IResult.cs

@@ -6,12 +6,18 @@ using System.Threading.Tasks;
 
 namespace StructureHelperCommon.Models.Calculators
 {
+    /// <summary>
+    /// Base interface of result of calculation
+    /// </summary>
     public interface IResult
     {
         /// <summary>
         /// True if result of calculation is valid
         /// </summary>
         bool IsValid { get; set; }
+        /// <summary>
+        /// Description of result of calculation
+        /// </summary>
         string? Description { get; set; }
     }
 }