Add textproc/py-xml-default-dict: Python scripts to convert xml data into a defaultdict

Simple lib to convert xml file into a defaultdict from python collections lib,
making more easy use the dict to accesses some tags of xml data.

WWW: https://github.com/kanazux/xml-default-dict

PR: 225382
Submitted by: Silvio Ap Silva <contato@kanazuchi.com>