[c++] Elegant Way to Pass the const char* const* input_names input to the Run function

[FabianSchuetze]

Is there a way to avoid the following coding pattern with the c++ api to pass the const char* const* input_names into the run function? (without hardcoding the input names into the executable)

- Copy the input names for the `session.GetInputNameAllocated(i, allocator)` to a `std::vector`. 
- The copy the std string of a std vector of const char* pointers. 

Especially with many inputs, this is cumbersome. The session object is alive all the time and holds the data already.