Add package ref for codepages

MediaBrowser.MediaEncoding/MediaBrowser.MediaEncoding.csproj

@@ -18,6 +18,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="System.Text.Encoding.CodePages" Version="4.5.1" />
     <PackageReference Include="UTF.Unknown" Version="1.0.0-beta1" />
   </ItemGroup>