Move logic of computing Blurhash components to ImageProcessor

Also rename last few instances of GetImageHash to GetImageBlurHash for clarity

Emby.Server.Implementations/Library/LibraryManager.cs

@@ -1882,6 +1882,7 @@ namespace Emby.Server.Implementations.Library
                 ImageDimensions size = _imageProcessor.GetImageDimensions(item, image);
                 image.Width = size.Width;
                 image.Height = size.Height;
+
                 try
                 {
                     image.BlurHash = _imageProcessor.GetImageBlurHash(image.Path);