Prevent duped decoupled entrances in spoiler log

[Archez]

After the change to have decoupled entrances in the spoiler log, it seems some entrances were in there twice.

Adding an !IsAddedToPool() for the reverse check similar to the top level check prevents duplicate records.

The only thing I can't fully comment on is if some of the decoupled entrances should be considered in a different "sphere". I'm not sure how the spheres are determined.