Misc Fixes (#839)

* Fixed a case where chapter was being parsed incorrectly when the series title ends in a number.

* Updated Kavita to support Tome/T notation found in French comics

* Added support for identifying European specials and expanded support for cleaning some tags used in European comics. During cleaning, if series starts with - or comma, remove it.

* Fixed an issue where add to collection for a single series wasn't calling the bulk action handler

* Fixed a NPE on AgeRating conversion. Fixed a bug where when looking for cover image, file extensions was throwing off sort code.

* Refactored Natural Sort ordering to better follow how Windows behaves. This is a departure from how the original code executes.

* GetCachedPagePath now uses natural sorting to pick the images for reading in a more correct order.

* Updated parser to handle a case where there was more than one space as a separator

API/Data/Metadata/ComicInfo.cs

@@ -74,6 +74,7 @@ namespace API.Data.Metadata
 
         public static AgeRating ConvertAgeRatingToEnum(string value)
         {
+            if (string.IsNullOrEmpty(value)) return Entities.Enums.AgeRating.Unknown;
             return Enum.GetValues<AgeRating>()
                 .SingleOrDefault(t => t.ToDescription().ToUpperInvariant().Equals(value.ToUpperInvariant()), Entities.Enums.AgeRating.Unknown);
         }