Create unit tests for Calculator plugin (#6356)

* Refactored logic and made it unit testable

* Changes after code review

* Added to build steps, and modified bracket to new class with unittest. Validates complexer cases now.

Co-authored-by: p-storm <paul.de.man@gmail.com>

src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/ResultHelper.cs

@@ -0,0 +1,53 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Globalization;
+using System.Runtime.InteropServices;
+using System.Threading;
+using System.Windows;
+using Wox.Plugin;
+
+namespace Microsoft.Plugin.Calculator
+{
+    public static class ResultHelper
+    {
+        public static Result CreateResult(CalculateResult result, string iconPath)
+        {
+            return CreateResult(result.Result, result.RoundedResult, iconPath);
+        }
+
+        public static Result CreateResult(decimal result, decimal roundedResult, string iconPath)
+        {
+            return new Result
+            {
+                Title = roundedResult.ToString(CultureInfo.CurrentCulture),
+                IcoPath = iconPath,
+                Score = 300,
+                SubTitle = Properties.Resources.wox_plugin_calculator_copy_number_to_clipboard,
+                Action = c => Action(result),
+            };
+        }
+
+        public static bool Action(decimal result)
+        {
+            var ret = false;
+            var thread = new Thread(() =>
+            {
+                try
+                {
+                    Clipboard.SetText(result.ToString(CultureInfo.CurrentUICulture.NumberFormat));
+                    ret = true;
+                }
+                catch (ExternalException)
+                {
+                    MessageBox.Show(Properties.Resources.wox_plugin_calculator_copy_failed);
+                }
+            });
+            thread.SetApartmentState(ApartmentState.STA);
+            thread.Start();
+            thread.Join();
+            return ret;
+        }
+    }
+}