video_core: Remove all Core::System references in renderer

Now that the GPU is initialized when video backends are initialized,
it's no longer needed to query components once the game is running: it
can be done when yuzu is booting.

This allows us to pass components between constructors and in the
process remove all Core::System references in the video backend.

src/yuzu_tester/yuzu.cpp

@@ -255,7 +255,6 @@ int main(int argc, char** argv) {
                                        "SDLHideTester");
 
     system.GPU().Start();
-    system.Renderer().Rasterizer().LoadDiskResources();
 
     system.Run();
     while (!finished) {