Perform Compressed<->Uncompressed copies using Pixel Buffer Objects (#1732)

* PBO single layer copy, part 1

Still needs ability to take and set width/height slices. (using pack paramaters)

* PBO Copies pt 2

* Some fixes and cleanup.

* Misc Cleanup

* Move handle into the TextureInfo interface.

This interface is shared between texture storages and views.

* Move unscaled copy to the TextureCopy class.

* Address feedback.

Ryujinx.Graphics.OpenGL/Image/ITextureInfo.cs

@@ -0,0 +1,10 @@
+using Ryujinx.Graphics.GAL;
+
+namespace Ryujinx.Graphics.OpenGL.Image
+{
+    interface ITextureInfo
+    {
+        int Handle { get; }
+        TextureCreateInfo Info { get; }
+    }
+}