GH-2859 improve UI for twitch pack import with drag&drop

application/widgets/DropLabel.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <QLabel>
+
+class DropLabel : public QLabel
+{
+    Q_OBJECT
+
+public:
+    explicit DropLabel(QWidget *parent = nullptr);
+
+signals:
+    void droppedURLs(QList<QUrl> urls);
+
+protected:
+    void dropEvent(QDropEvent *event) override;
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dragLeaveEvent(QDragLeaveEvent *event) override;
+};