Offscreen Raytraced Light Sampling Bug Fixed. (Patreon)

I've fixed a bug where offscreen BSP entities weren't occluding traces.

In this video, you can see the bug. When the button on the wall goes offscreen, it stops blocking the light, and its shadow disappears.

This bug happened because Retroquad was only tracing against entities that passes the R_BmodelCheckBBox check, and this function clips entities against the view frustum. Now I'm using a different check on the traces.