Import py-Levenshtein-0.12.0 as textproc/py-Levenshtein

The Levenshtein Python C extension module contains functions for fast
computation of: Levenshtein (edit) distance and edit operations, string
similarity, approximate median strings and general string averaging,
and string sequence and set similarity. It supports both normal and
Unicode strings.

Packaged by David H. Gutteridge via PR pkg/52017

(leot)