Formatting CLI metrics (dotnet#264)

Ensures space between printed metrics (also model counter). Right aligned metrics. Extended AUC to four digits.

Author: justinormont

src/mlnet/Utilities/ConsolePrinter.cs

@@ -12,28 +12,28 @@ internal class ConsolePrinter
         private static NLog.Logger logger = NLog.LogManager.GetCurrentClassLogger();
         internal static void PrintRegressionMetrics(int iteration, string trainerName, RegressionMetrics metrics)
         {
-            logger.Log(LogLevel.Info, $"{iteration,-4}{trainerName,-35}{metrics.RSquared,-10:F4}{metrics.LossFn,-8:F2}{metrics.L1,-15:F2}{metrics.L2,-15:F2}{metrics.Rms,-10:F2}");
+            logger.Log(LogLevel.Info, $"{iteration,4} {trainerName,-35} {metrics.RSquared,9:F4} {metrics.LossFn,12:F2} {metrics.L1,15:F2} {metrics.L2,15:F2} {metrics.Rms,12:F2}");
         }
 
         internal static void PrintBinaryClassificationMetrics(int iteration, string trainerName, BinaryClassificationMetrics metrics)
         {
-            logger.Log(LogLevel.Info, $"{iteration,-4}{trainerName,-35}{metrics.Accuracy,-10:F4}{metrics.Auc,-8:F2}");
+            logger.Log(LogLevel.Info, $"{iteration,4} {trainerName,-35} {metrics.Accuracy,9:F4} {metrics.Auc,8:F4}");
         }
 
         internal static void PrintBinaryClassificationMetricsHeader()
         {
             logger.Log(LogLevel.Info, $"*************************************************");
             logger.Log(LogLevel.Info, $"*       {Strings.MetricsForBinaryClassModels}     ");
             logger.Log(LogLevel.Info, $"*------------------------------------------------");
-            logger.Log(LogLevel.Info, $"{" ",-4}{"Trainer",-35}{"Accuracy",-10}{"Auc",-8}");
+            logger.Log(LogLevel.Info, $"{" ",4} {"Trainer",-35} {"Accuracy",9} {"AUC",8}");
         }
 
         internal static void PrintRegressionMetricsHeader()
         {
             logger.Log(LogLevel.Info, $"*************************************************");
             logger.Log(LogLevel.Info, $"*       {Strings.MetricsForRegressionModels}     ");
             logger.Log(LogLevel.Info, $"*------------------------------------------------");
-            logger.Log(LogLevel.Info, $"{" ",-4}{"Trainer",-35}{"R2-Score",-10}{"LossFn",-8}{"Absolute-loss",-15}{"Squared-loss",-15}{"RMS-loss",-10}");
+            logger.Log(LogLevel.Info, $"{" ",4} {"Trainer",-35} {"R2-Score",9} {"LossFn",12} {"Absolute-loss",15} {"Squared-loss",15} {"RMS-loss",12}");
         }
 
         internal static void PrintBestPipelineHeader()