Transfer of Chemist #302: Better change_input API

[ryanmrichard]

I think this issue makes more sense here so I copy/pasted it (and I guess you can't use the transfer issue API to move an issue from a private repo to a public repo).

The C++ signature is: template <typename T> void Module::change_input(const std::string&, T&& value). T is an implicit template type parameter (i.e., C++ doesn't require you to specify it). So in C++ I can do something like:

mod.change_input("Number of iterations", 100);

But from Python I need to do:

mod.change_input["unsigned int"]("Number of iterations", 100)

The need to implicitly set the type is very non-Pythonic.

[wadejong]

Same as https://github.com/NWChemEx-Project/.github/issues/35