[PR] Makes prodoc heart unaffected by lighting

[BatElite]

I figured there'd be issues with it.
One thing I could do is vary the heart's transparency with how lit the area is
There's a few other problems in turn though:
-Still shows through trees
-Unaffected by simple lights, so flashlights can't help in the dark here.
-The heart updates with the life loop, so there's a delay
-space isn't lit (which is an easy fix but presumably there's more weird cases)

Let me know if that's any better, but I'm not sure if it is all that easy to salvage.