Replace std::decay with std::remove_cvref after C++20

[AlCash07]

C++20 will have a new trait std::remove_cvref that doesn't have undesirable effect of std::decay on arrays, so maybe it's worth using it for example here:

zoo/inc/meta/NotBasedOn.h

Line 14 in d59092a

using DecayedT = std::decay_t<T>;