Remove duplicate files like pack.hpp, type_traits.hpp, unbounded_shift.hpp, endian_shift.hpp etc.

[martun]

Files pack.hpp, type_traits.hpp, unbounded_shift.hpp, endian_shift.hpp are copied into all the repos. I'm not even sure which repo is supposed to have these file, but they use the same #ifdef-s, which means that we need to keep them identical, otherwise it's not clear which one will be used in the crypto3-zk project. (many of them will get included from different sources)