Feature/rating pop up (#760)

* WIP

* WIP

* Add text

* Cleanup

* More Cleanup

* Update Changelog

* Fix layout

---------

Co-authored-by: Florian Schulze <flori.schulze@yahoo.de>
Co-authored-by: Florian Ostertag <flokuep@users.noreply.github.com>

VocaluxeLib/Structs.cs

@@ -346,12 +346,15 @@ namespace VocaluxeLib
         public double PointsLineBonus;
         public double PointsGoldenNotes;
         public double Rating;
+        public double RatingLastLine;
         public int NoteDiff;
         public int VoiceNr;
         public List<CSungLine> SungLines;
         public int CurrentLine;
         public int CurrentNote;
 
+        public float TimeLastLineChange;
+
         public int SongID;
         public EGameMode GameMode;
         public long DateTicks;