Use CTTI instead of RTTI where possible

[usachev63]

In some projects we are required to use -fno-rtti option, which disables RTTI (run-time type information). cereal uses typeid operator, which requires RTTI, in the following two scenarios:

1. using typeid on a type which is known at compile-time (usually taking hash_code() of the returned std::type_info);
2. using typeid in order to support serialization of polymorphic types (i.e. here types are not known at compile time), see polymorphic.hpp.

While usage in the scenario 2 is required to serialize polymorphic types, we don't need RTTI at all in scenario 1.

This PR replaced all usages of typeid having a compile-time known type with methods from an external library ctti (open source, MIT license) - this library provides ctti::type_id<T>() functions for compile-time type id, and also ctti::type_id_t type, similar to std::type_info.

With this change one can use cereal with -fno-rtti flag, in case when one does not serialize any polymorphic types (i.e. does not include polymorphic.hpp or other related headers).

[usachev63]

Converted to draft because there is at least another instance of using typeid with compile-time known type: see util.hpp