optimise ppu rendering

[ITotalJustice]

in emerald, without rendering: 1k fps with rendering: 450-460 fps

thats just over half of my fps gone just because of rendering 160 times a frame.

1. only calculate window tables on window values changing
2. template rendering to skip blending / windowing checks if disabled
3. cache decoded screen entries (likely not worth it)
4. cache decoded oam entries

1: this should give a decent speed up, but still not by much.

2: while this will speed up scenes that dont use windowing and blending, this still isn't ideal because many scenes do use both windowing and blending. so those scenes will still be super slow.

3: decoding is very fast already.

4: this will be a decent speed up.