feat: add C `ndarray` interface and refactor implementation for `stats/base/dsmeanpw`#4338

kgryte merged 13 commits intostdlib-js:developstdlib-js/stdlib:developfrom

Neerajpathak07:ndarray-dsmeanpwNeerajpathak07/stdlib:ndarray-dsmeanpwCopy head branch name to clipboard