Set SmoothPixmapTransform for playing-widget and context album art display

src/context/contextalbum.cpp

@@ -114,6 +114,8 @@ void ContextAlbum::paintEvent(QPaintEvent*) {
 }
 
 void ContextAlbum::DrawImage(QPainter *p) {
+  
+  p->setRenderHint(QPainter::SmoothPixmapTransform);
 
   if (width() != prev_width_) {
     cover_loader_options_.desired_height_ = width() - kWidgetSpacing;

src/widgets/playingwidget.cpp

@@ -438,6 +438,8 @@ void PlayingWidget::paintEvent(QPaintEvent *e) {
 
 void PlayingWidget::DrawContents(QPainter *p) {
 
+  p->setRenderHint(QPainter::SmoothPixmapTransform);
+
   switch (mode_) {
     case SmallSongDetails:
       // Draw the cover