Move support buffer update out of the backends (#5411)

* Move support buffer update out of the backends

* Fix render scale init and remove redundant state from SupportBufferUpdater

* Stop passing texture scale to the backends

* XML docs for SupportBufferUpdater

src/Ryujinx.Graphics.Vulkan/Effects/FxaaPostProcessingEffect.cs

@@ -57,7 +57,7 @@ namespace Ryujinx.Graphics.Vulkan.Effects
             if (_texture == null || _texture.Width != view.Width || _texture.Height != view.Height)
             {
                 _texture?.Dispose();
-                _texture = _renderer.CreateTexture(view.Info, view.ScaleFactor) as TextureView;
+                _texture = _renderer.CreateTexture(view.Info) as TextureView;
             }
 
             _pipeline.SetCommandBuffer(cbs);