Replace use of `const std::vector<T> &` with `std::span<const T>` in arguments

Many of our APIs have a `const vector` passed by reference (i.e. `const std::vector<T> &`). We can make these APIs more flexible (i.e. able to take a wider range of arguments) if we switch to `std::span<const T>`. Passing a `std::vector` will still work so it should just be a case of changing the declarations and perhaps some of the logic related to handling the argument in the implementation.