[C++] Add pairwise_diff function

### Describe the enhancement requested

Similar to pandas' [Series.Diff](https://pandas.pydata.org/docs/reference/api/pandas.Series.diff.html), the `pairwise_diff` function computes the first order difference of an array, i.e. output[i] = input[i] - input[i-period] where period is configurable.

### Component(s)

C++