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.OpenGL/Image/IntermmediatePool.cs

@@ -87,7 +87,7 @@ namespace Ryujinx.Graphics.OpenGL.Image
                 SwizzleComponent.Red,
                 SwizzleComponent.Green,
                 SwizzleComponent.Blue,
-                SwizzleComponent.Alpha), 1f);
+                SwizzleComponent.Alpha));
         }
 
         public void Dispose()