chore: adjusted the project directory structure

app/metadatadialog.h

@@ -0,0 +1,26 @@
+#ifndef METADATADIALOG_H
+#define METADATADIALOG_H
+
+#include <QDialog>
+
+QT_BEGIN_NAMESPACE
+class QTreeView;
+QT_END_NAMESPACE
+
+class MetadataModel;
+class MetadataDialog : public QDialog
+{
+    Q_OBJECT
+public:
+    explicit MetadataDialog(QWidget * parent);
+    ~MetadataDialog() override;
+
+    void setMetadataModel(MetadataModel * model);
+
+    QSize sizeHint() const override;
+
+private:
+    QTreeView * m_treeView = nullptr;
+};
+
+#endif // METADATADIALOG_H