Context: Use custom textedits instead of labels

Also improve album cover scaling

Fixes #965

src/context/contextalbum.h

@@ -1,6 +1,6 @@
 /*
  * Strawberry Music Player
- * Copyright 2020-2021, Jonas Kvinge <jonas@jkvinge.net>
+ * Copyright 2020-2022, Jonas Kvinge <jonas@jkvinge.net>
  *
  * Strawberry is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -52,6 +52,7 @@ class ContextAlbum : public QWidget {
   void SetImage(QImage image = QImage());
 
  protected:
+  QSize sizeHint() const override;
   void paintEvent(QPaintEvent*) override;
   void contextMenuEvent(QContextMenuEvent *e) override;
   void mouseDoubleClickEvent(QMouseEvent *e) override;