Move GPU emulation from Ryujinx.HLE to Ryujinx.Graphics and misc changes (#402)

* Move GPU LLE emulation from HLE to Graphics

* Graphics: Move Gal/Texture to Texture

* Remove Engines/ directory and namespace

* Use tables for image formats

* Abstract OpCode decoding

* Simplify image table

* Do not leak Read* symbols in TextureReader

* Fixups

* Rename IGalFrameBuffer -> IGalRenderTarget

* Remove MaxBpp hardcoded value

* Change yet again texture data and add G8R8 flipping

* Rename GalFrameBufferFormat to GalSurfaceFormat

* Unident EnsureSetup in ImageHandler

* Add IsCompressed

* Address some feedback

Ryujinx.Graphics/NvGpuFifoMeth.cs

@@ -0,0 +1,11 @@
+namespace Ryujinx.Graphics
+{
+    enum NvGpuFifoMeth
+    {
+        BindChannel           = 0,
+        SetMacroUploadAddress = 0x45,
+        SendMacroCodeData     = 0x46,
+        SetMacroBindingIndex  = 0x47,
+        BindMacro             = 0x48
+    }
+}