[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/shaders/guest_output_triangle_strip_rect.vert

@@ -0,0 +1,17 @@
+#version 310 es
+
+layout(push_constant) uniform XeTriangleStripRectConstants {
+  // If the layout is changed, update the base offset in all guest output
+  // fragment shaders!
+  vec2 xe_triangle_strip_rect_offset;
+  // Can be negative.
+  vec2 xe_triangle_strip_rect_size;
+};
+
+void main() {
+  // Passthrough - coordinate system differences are to be handled externally.
+  gl_Position = vec4(xe_triangle_strip_rect_offset +
+                         vec2((uvec2(gl_VertexIndex) >> uvec2(0u, 1u)) & 1u) *
+                         xe_triangle_strip_rect_size,
+                     0.0, 1.0);
+}