Replace old Imgui renderer with Direct3D renderer

[sourpuh]

1. Rewrote all shape screen drawing code to use D3D buffers and shaders
2. As a side effect of the rewrite, renderable zones now have negligible performance loss
3. Added support for up to 32 clip zones as an alternative to renderable zones
4. Switched blending to now use maximum alpha instead of additive alpha

[Limiana]

Thank you!