FifoRecorder: Use Video Common to record efb2ram correctly.

Texture updates have been moved into TextureCache, while
TMEM updates where moved into bpmem. Code for handling
efb2ram updates was added to TextureCache.

There was a bug for preloaded RGBA8 textures, it only copied
half the texture. The TODO was wrong too.

Source/Core/VideoCommon/OpcodeDecoding.h

@@ -38,8 +38,6 @@
 #define GX_DRAW_LINE_STRIP          0x6   // 0xB0
 #define GX_DRAW_POINTS              0x7   // 0xB8
 
-extern bool g_bRecordFifoData;
-
 void OpcodeDecoder_Init();
 void OpcodeDecoder_Shutdown();