yuzu: Implement Vulkan frontend

Adds a Qt and SDL2 frontend for Vulkan. It also finishes the missing
bits on Vulkan initialization.

src/yuzu/configuration/configure_graphics.h

@@ -5,7 +5,10 @@
 #pragma once
 
 #include <memory>
+#include <vector>
+#include <QString>
 #include <QWidget>
+#include "core/settings.h"
 
 namespace Ui {
 class ConfigureGraphics;
@@ -27,7 +30,16 @@ private:
     void SetConfiguration();
 
     void UpdateBackgroundColorButton(QColor color);
+    void UpdateDeviceComboBox();
+    void UpdateDeviceSelection(int device);
+
+    void RetrieveVulkanDevices();
+
+    Settings::RendererBackend GetCurrentGraphicsBackend() const;
 
     std::unique_ptr<Ui::ConfigureGraphics> ui;
     QColor bg_color;
+
+    std::vector<QString> vulkan_devices;
+    u32 vulkan_device{};
 };