[Qt] Settings Window for Qt

AND Fix leftovers from full code, fixed styling and lint

Source/Core/DolphinQt2/Config/SettingsWindow.h

@@ -0,0 +1,37 @@
+// Copyright 2015 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <QDialog>
+#include <QDialogButtonBox>
+#include <QGroupBox>
+#include <QHBoxLayout>
+#include <QLabel>
+#include <QListView>
+#include <QListWidget>
+#include <QListWidgetItem>
+#include <QStackedWidget>
+#include <QString>
+#include <QVBoxLayout>
+#include <QWidget>
+
+class SettingsWindow final : public QDialog
+{
+    Q_OBJECT
+public:
+    explicit SettingsWindow(QWidget* parent = nullptr);
+
+public slots:
+    void changePage(QListWidgetItem* current, QListWidgetItem* previous);
+
+private:
+    void MakeCategoryList();
+    void MakeUnfinishedWarning();
+    void AddCategoryToList(const QString& title, const QString& icon);
+    void SetupSettingsWidget();
+    QStackedWidget* m_settings_outer;
+    QListWidget* m_categories;
+    QGroupBox* m_warning_group;
+};