Add initial work on Qt frontend

src/duckstation-qt/gamelistsettingswidget.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <QtWidgets/QWidget>
+
+#include "ui_gamelistsettingswidget.h"
+
+class QtHostInterface;
+
+class GameListSearchDirectoriesModel;
+
+class GameListSettingsWidget : public QWidget
+{
+  Q_OBJECT
+
+public:
+  GameListSettingsWidget(QtHostInterface* host_interface, QWidget* parent = nullptr);
+  ~GameListSettingsWidget();
+
+private Q_SLOTS:
+  void onAddSearchDirectoryButtonPressed();
+  void onRemoveSearchDirectoryButtonPressed();
+  void onRefreshGameListButtonPressed();
+  void onBrowseRedumpPathButtonPressed();
+  void onDownloadRedumpDatabaseButtonPressed();
+
+protected:
+  void resizeEvent(QResizeEvent* event);
+
+private:
+  QtHostInterface* m_host_interface;
+
+  Ui::GameListSettingsWidget m_ui;
+
+  GameListSearchDirectoriesModel* m_search_directories_model = nullptr;
+};