Farlands Tweaks Core 1.3 - BFC / Embeddium AU/PHASE2 compatibility

When Brute Force Culling Revived 2.2 targets the legacy
OcclusionCuller.isSectionVisible hook but the installed Embeddium build no longer
exposes that method, Core registers a MixinSquared cancellation for only BFC's
sodium.MixinOcclusionCuller.

On Embeddium PHASE2 builds exposing computePassVisibility, FarlandsTweaks supplies
an equivalent replacement that preserves BFC early main-camera chunk occlusion
while keeping PHASE2 additional visibility-pass bits intact.
