Graphics Module Cleanup

[TurtleP]

I've spoken with @piepie62 about this before, but it's kinda a pain point that I think can be resolved. Perhaps Delta also has some input, but we'll see. Essentially, before I get back into 3.0's work, I need to figure out how to clean up the graphics module. It's kinda bulky and getting really annoying to deal with. While I understand I have to implement console-specific stuff for each derived class, the problem is that Switch and Wii U will be sharing a lot of functionality (especially in primitive rendering).

I'm pretty sure I already did something similar with ImageData, so I should be able to do that here: basically make Graphics<Console::ALL> default implement for the Switch and Wii U code for primitive rendering, then the 3DS will have its own derived class to do its own thing. The only problem, though, is that the DrawCommand struct that is necessary for this to work is console-specific.. although I can move that out to its own header file. That could probably solve it.

Thoughts?

[TurtleP]

@piepie62 has agreed that the idea behind this cleanup is a good choice. See #194 for the issue tracking this.