[Feature Request] [Feature Idea] Different types of walls (semipermeable walls)

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Different types of walls would be pretty cool. Some that I can think of right off the type of my head:

• walls which movers can not cross
• wall which producers can not cross (creatures with out a mover cell)
• walls that only let certain size of creature through (or maybe a range of sizes)

I have been super interested in trying to evolve small creatures. So far I have made walls with one cell gaps and hope something can pass through this "mesh". But this limits me to only one size. I cant try to evolve bigger creatures like this since anything smaller than the gap can fit through

Semi related: Maybe I will make this its own issue, but maybe an option to not remove walls on reset?