Change scultpure observing formula

- The scultpure was using checks that caused serious problem. To be
consise, if the statue was 4 tiles north and three tiles east, and a
player faced east, the statue would consider itself not observed
- It was changed into a much more straightforward and far less spergy
check. Is SCP on the same x plane ? No ? If we are facing him, observed,
same with y

This might need finetuning, as this effectively means SCP can be stopped
even by a 180-ish° face-off