[UI] Image post-processing and full presentation/window rework

[GPU] Add FXAA post-processing
[UI] Add FidelityFX FSR and CAS post-processing
[UI] Add blue noise dithering from 10bpc to 8bpc
[GPU] Apply the DC PWL gamma ramp closer to the spec, supporting fully white color
[UI] Allow the GPU CP thread to present on the host directly, bypassing the UI thread OS paint event
[UI] Allow variable refresh rate (or tearing)
[UI] Present the newest frame (restart) on DXGI
[UI] Replace GraphicsContext with a far more advanced Presenter with more coherent surface connection and UI overlay state management
[UI] Connect presentation to windows via the Surface class, not native window handles
[Vulkan] Switch to simpler Vulkan setup with no instance/device separation due to interdependencies and to pass fewer objects around
[Vulkan] Lower the minimum required Vulkan version to 1.0
[UI/GPU] Various cleanup, mainly ComPtr usage
[UI] Support per-monitor DPI awareness v2 on Windows
[UI] DPI-scale Dear ImGui
[UI] Replace the remaining non-detachable window delegates with unified window event and input listeners
[UI] Allow listeners to safely destroy or close the window, and to register/unregister listeners without use-after-free and the ABA problem
[UI] Explicit Z ordering of input listeners and UI overlays, top-down for input, bottom-up for drawing
[UI] Add explicit window lifecycle phases
[UI] Replace Window virtual functions with explicit desired state, its application, actual state, its feedback
[UI] GTK: Apply the initial size to the drawing area
[UI] Limit internal UI frame rate to that of the monitor
[UI] Hide the cursor using a timer instead of polling due to no repeated UI thread paints with GPU CP thread presentation, and only within the window

src/xenia/ui/ui_drawer.h

@@ -0,0 +1,38 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2022 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_UI_DRAWER_H_
+#define XENIA_UI_UI_DRAWER_H_
+
+#include <cstdint>
+
+namespace xe {
+namespace ui {
+
+class UIDrawContext;
+
+class UIDrawer {
+ public:
+  // No preparation or finishing callbacks because drawers may register or
+  // unregister each other, so between the loops the list may be different.
+
+  // The draw function may register or unregister drawers (and depending on the
+  // Z order the changes may or may not effect immediately). However, they must
+  // not perform any lifetime management of the presenter and of its connection
+  // to the surface. Ideally drawing should not be changing any state at all,
+  // however, in Dear ImGui, input is handled directly during drawing - any
+  // quitting or resizing, if done in the UI, must be deferred via something
+  // like WindowedAppContext::CallInUIThreadDeferred.
+  virtual void Draw(UIDrawContext& context) = 0;
+};
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_UI_DRAWER_H_