Add GFX property tabs to game properties window, allowing them to be set to the user game ini. Additionally, refactor ConfigWidgets to reduce duplication. Refactor GameConfigWidget to use config system.

Creates a layer outside the game config layer system and passes it to the created gfx widows, so as to not interfere with the global config system.

Supports multiple game properties being open at once.
Supports editing while a game is playing, but the options only save and update the active game when the window is closed.
Right-clicking will remove a property from the game ini.

Source/Core/DolphinQt/Config/Graphics/EnhancementsWidget.h

@@ -10,6 +10,7 @@
 class ConfigBool;
 class ConfigChoice;
 class ConfigSlider;
+class GameConfigWidget;
 class GraphicsWindow;
 class QCheckBox;
 class QComboBox;
@@ -19,11 +20,17 @@ class ToolTipComboBox;
 class ToolTipPushButton;
 enum class StereoMode : int;
 
+namespace Config
+{
+class Layer;
+}  // namespace Config
+
 class EnhancementsWidget final : public QWidget
 {
   Q_OBJECT
 public:
   explicit EnhancementsWidget(GraphicsWindow* parent);
+  EnhancementsWidget(GameConfigWidget* parent, Config::Layer* layer);
 
 private:
   void LoadSettings();
@@ -60,6 +67,7 @@ private:
   ConfigBool* m_3d_swap_eyes;
   ConfigBool* m_3d_per_eye_resolution;
 
+  Config::Layer* m_game_layer = nullptr;
   int m_msaa_modes;
   bool m_block_save;
 };