Start: Fix memory leak

* Set parent object to FileCardDelegate so that it will be destroyed if the list view is destroyed
* Inside FileCardDelegate::paint() delete the widget

src/Mod/Start/Gui/FileCardDelegate.cpp

@@ -164,6 +164,7 @@ void FileCardDelegate::paint(QPainter* painter,
     widget->render(painter, QPoint(), QRegion(), QWidget::DrawChildren);
     painter->restore();
     delete pixmap;
+    delete widget;
 }
 
 

src/Mod/Start/Gui/StartView.cpp

@@ -266,7 +266,7 @@ QString StartView::fileCardStyle() const
 
 void StartView::configureFileCardWidget(QListView* fileCardWidget)
 {
-    auto delegate = gsl::owner<FileCardDelegate*>(new FileCardDelegate);
+    auto delegate = gsl::owner<FileCardDelegate*>(new FileCardDelegate(fileCardWidget));
     fileCardWidget->setItemDelegate(delegate);
     fileCardWidget->setMinimumWidth(fileCardWidget->parentWidget()->width());
     //    fileCardWidget->setGridSize(