Missing includes of some std types

[aleasims]

In number of files some includes are missing:

/root/proj/zkllvm/libs/crypto3/libs/zk/include/nil/crypto3/zk/snark/arithmetization/plonk/variable.hpp:170:26: error: no template named 'map' in namespace 'std'; did you mean 'max'?
                    std::map<typename plonk_variable<AssignmentType>::column_type, std::string> type_map = {
                    ~~~~~^~~
                         max

/root/proj/zkllvm/libs/crypto3/libs/zk/include/nil/crypto3/zk/snark/arithmetization/plonk/constraint.hpp:48:30: error: no template named 'map' in namespace 'std'; did you mean 'max'?
                        std::map<std::tuple<std::size_t, int, typename VariableType::column_type>,
                        ~~~~~^~~
                             max

This results in compilation errors, when these files get included.

Of course, user can include these headers on his side, but adding it here seems more sound.