Add array input support for the thor functor grammar

As discussed in #424 (comment 6182405), this MR will add a new Functor grammar to the standard array module in python. This is useful for array input in Functor F.VALUE_OR, since in C++ one can never construct a std::vector<double> directly from std::vector<float> as shown below:

std::vector<float> input_for_value_or { -999.f};
std::vector<double> output {input_for_value_or};  // Error! this can't be compiled

The standard array model in python will allow you to specify the type of array using the typecode, in which array('f',[...]) will correspond to an std::vector<float> and array('d',[...]) will correspond to a std::vector<double> in this new grammar.

Necessary tests are included in this MR.

This MR should be tested with Analysis!948 (merged)

FYI: @amathad @erodrigu @pkoppenb @graven