Fix translation context.

Partially addresses #8220.

Also sort include headers

src/gui/search/searchlistdelegate.cpp

@@ -28,14 +28,20 @@
  * Contact : chris@qbittorrent.org
  */
 
-#include <QStyleOptionViewItem>
+#include <QCoreApplication>
 #include <QModelIndex>
 #include <QPainter>
 #include <QProgressBar>
+#include <QStyleOptionViewItem>
 
 #include "base/utils/misc.h"
-#include "searchsortmodel.h"
 #include "searchlistdelegate.h"
+#include "searchsortmodel.h"
+
+namespace
+{
+    const char i18nContext[] = "SearchListDelegate";
+}
 
 SearchListDelegate::SearchListDelegate(QObject *parent)
     : QItemDelegate(parent)
@@ -57,7 +63,8 @@ void SearchListDelegate::paint(QPainter *painter, const QStyleOptionViewItem &op
     case SearchSortModel::SEEDS:
     case SearchSortModel::LEECHES:
         opt.displayAlignment = Qt::AlignRight | Qt::AlignVCenter;
-        QItemDelegate::drawDisplay(painter, opt, option.rect, (index.data().toLongLong() >= 0) ? index.data().toString() : tr("Unknown"));
+        QItemDelegate::drawDisplay(painter, opt, option.rect
+            , (index.data().toLongLong() >= 0) ? index.data().toString() : QCoreApplication::translate(i18nContext, "Unknown"));
         break;
     default:
         QItemDelegate::paint(painter, option, index);