New: Add additional logging when renaming extra files

(cherry picked from commit 1ae0dc81f73ef74078f07fd5536a7d9058df649d)

Closes #2782

src/NzbDrone.Core/Extras/Files/ExtraFile.cs

@@ -12,5 +12,10 @@ namespace NzbDrone.Core.Extras.Files
         public DateTime Added { get; set; }
         public DateTime LastUpdated { get; set; }
         public string Extension { get; set; }
+
+        public override string ToString()
+        {
+            return $"[{Id}] {RelativePath}";
+        }
     }
 }

src/NzbDrone.Core/Extras/Files/ExtraFileManager.cs

@@ -81,6 +81,8 @@ namespace NzbDrone.Core.Extras.Files
 
         protected TExtraFile MoveFile(Author author, BookFile bookFile, TExtraFile extraFile, string fileNameSuffix = null)
         {
+            _logger.Trace("Renaming extra file: {0}", extraFile);
+
             var newFolder = Path.GetDirectoryName(bookFile.Path);
             var filenameBuilder = new StringBuilder(Path.GetFileNameWithoutExtension(bookFile.Path));
 
@@ -98,9 +100,13 @@ namespace NzbDrone.Core.Extras.Files
             {
                 try
                 {
+                    _logger.Trace("Renaming extra file: {0} to {1}", extraFile, newFileName);
+
                     _diskProvider.MoveFile(existingFileName, newFileName);
                     extraFile.RelativePath = author.Path.GetRelativePath(newFileName);
 
+                    _logger.Trace("Renamed extra file from: {0}", extraFile);
+
                     return extraFile;
                 }
                 catch (Exception ex)