read/parse file tags

import audiofiles

include/Tag.h

@@ -1,8 +1,10 @@
 #pragma once
 
 #include "Metadata.h"
+#include <memory>
 #include <taglib/tstring.h>
 #include <taglib/fileref.h>
+#include <taglib/tvariant.h>
 
 
 class Tag {
@@ -10,7 +12,8 @@ class Tag {
         void readTag( TagLib::FileName fileName );
         Metadata getMetadata() const;
 
-        std::string& getFilePath() const;
+        const std::string& getFilePath() const;
+        const auto getArtwork() const;
     private:
         Metadata metadata_;
         std::string filePath_;