Qt: Fix game list icons when toggling disc set merging

Also, make sure we call beginFilterChange() in the proxy model
as mentioned in the Qt docs.

src/duckstation-qt/gamelistwidget.cpp

@@ -143,11 +143,15 @@ void GameListModel::setShowGameIcons(bool enabled)
 {
   m_show_game_icons = enabled;
 
-  beginResetModel();
-  m_memcard_pixmap_cache.Clear();
   if (enabled)
     GameList::ReloadMemcardTimestampCache();
-  endResetModel();
+  refreshIcons();
+}
+
+void GameListModel::refreshIcons()
+{
+  m_memcard_pixmap_cache.Clear();
+  emit dataChanged(index(0, Column_Icon), index(rowCount() - 1, Column_Icon), {Qt::DecorationRole});
 }
 
 void GameListModel::setCoverScale(float scale)
@@ -305,7 +309,7 @@ void GameListModel::rowsChanged(const QList<int>& rows)
     }
     else
     {
-      emit dataChanged(createIndex(rows[start], 0), createIndex(rows[idx], Column_Count - 1), roles_changed);
+      emit dataChanged(index(rows[start], 0), index(rows[idx], Column_Count - 1), roles_changed);
       start = ++idx;
     }
   }
@@ -939,24 +943,28 @@ public:
 
   void setMergeDiscSets(bool enabled)
   {
+    beginFilterChange();
     m_merge_disc_sets = enabled;
     invalidateRowsFilter();
   }
 
   void setFilterType(GameList::EntryType type)
   {
+    beginFilterChange();
     m_filter_type = type;
     invalidateRowsFilter();
   }
 
   void setFilterRegion(DiscRegion region)
   {
+    beginFilterChange();
     m_filter_region = region;
     invalidateRowsFilter();
   }
 
   void setFilterName(std::string name)
   {
+    beginFilterChange();
     m_filter_name = std::move(name);
     std::transform(m_filter_name.begin(), m_filter_name.end(), m_filter_name.begin(), StringUtil::ToLower);
     invalidateRowsFilter();
@@ -1241,11 +1249,6 @@ void GameListWidget::refresh(bool invalidate_cache)
   m_refresh_thread->start();
 }
 
-void GameListWidget::refreshModel()
-{
-  m_model->refresh();
-}
-
 void GameListWidget::cancelRefresh()
 {
   if (!m_refresh_thread)
@@ -1445,6 +1448,7 @@ void GameListWidget::setMergeDiscSets(bool enabled)
   Host::SetBaseBoolSettingValue("UI", "GameListMergeDiscSets", enabled);
   Host::CommitBaseSettingChanges();
   m_sort_model->setMergeDiscSets(enabled);
+  m_model->refreshIcons();
 }
 
 void GameListWidget::setShowGameIcons(bool enabled)

src/duckstation-qt/gamelistwidget.h

@@ -90,6 +90,7 @@ public:
   bool getShowGameIcons() const { return m_show_game_icons; }
   void setShowGameIcons(bool enabled);
   QIcon getIconForGame(const QString& path);
+  void refreshIcons();
 
   float getCoverScale() const { return m_cover_scale; }
   void setCoverScale(float scale);
@@ -101,10 +102,8 @@ public:
 Q_SIGNALS:
   void coverScaleChanged(float scale);
 
-private Q_SLOTS:
-  void rowsChanged(const QList<int>& rows);
-
 private:
+  void rowsChanged(const QList<int>& rows);
   QVariant data(const QModelIndex& index, int role, const GameList::Entry* ge) const;
 
   void loadCommonImages();
@@ -164,11 +163,10 @@ public:
 protected:
   void resizeEvent(QResizeEvent* e) override;
 
-private Q_SLOTS:
+private:
   void onHeaderSortIndicatorChanged(int, Qt::SortOrder);
   void onHeaderContextMenuRequested(const QPoint& point);
 
-private:
   void loadColumnVisibilitySettings();
   void loadColumnSortSettings();
   void saveColumnSortSettings();
@@ -198,10 +196,8 @@ protected:
   void wheelEvent(QWheelEvent* e) override;
   void resizeEvent(QResizeEvent* e) override;
 
-private Q_SLOTS:
-  void onCoverScaleChanged(float scale);
-
 private:
+  void onCoverScaleChanged(float scale);
   void adjustZoom(float delta);
 
   GameListModel* m_model = nullptr;
@@ -226,7 +222,6 @@ public:
   void resizeListViewColumnsToFit();
 
   void refresh(bool invalidate_cache);
-  void refreshModel();
   void cancelRefresh();
   void reloadThemeSpecificImages();
   void updateBackground(bool reload_image);

src/duckstation-qt/mainwindow.cpp

@@ -2738,7 +2738,7 @@ void MainWindow::refreshGameList(bool invalidate_cache)
 
 void MainWindow::refreshGameListModel()
 {
-  m_game_list_widget->refreshModel();
+  m_game_list_widget->getModel()->refresh();
 }
 
 void MainWindow::cancelGameListRefresh()