Support directional opacity

[muzikbike]

Vanilla 1.14 implemented a system for this which is basically flawless, besides the few blocks that never ended up being special cased like cauldrons and carpets. Since we're reworking lighting in this mod, and some blocks are opaque to some colors of light but not others, this seems like a reasonable thing to consider.

With the mod:

1.21.4:

[basdxz]

Pulled from RPLE -> Lumi, as this feature would need to be implemented on this side.

Not currently planned.