Correct TestResultToOutcomeTextConverter

Was compairing against `TestResult` causing all results to return null.

Author: IvenBach

Rubberduck.Core/UI/UnitTesting/TestResultToOutcomeTextConverter.cs

@@ -10,9 +10,9 @@ public class TestResultToOutcomeTextConverter : IValueConverter
     {
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
         {
-            if (value is TestResult result)
+            if (value is TestOutcome result)
             {
-                return TestExplorer.ResourceManager.GetString("TestOutcome_" + result.Outcome, CultureInfo.CurrentUICulture);
+                return TestExplorer.ResourceManager.GetString($"TestOutcome_{result}", CultureInfo.CurrentUICulture);
             }
 
             return null;