process graphics element yaml files with scriban (#2410)

* add content rating to media item template

* process graphics element yaml files with scriban

ErsatzTV.Core/Interfaces/Metadata/ILocalFileSystem.cs

@@ -15,4 +15,5 @@ public interface ILocalFileSystem
     Task<Either<BaseError, Unit>> CopyFile(string source, string destination);
     Unit EmptyFolder(string folder);
     Task<string> ReadAllText(string path);
+    Task<string[]> ReadAllLines(string path);
 }