Python module to validate VAT numbers

Optional dependency: suds (e.g. python3-suds-jurko on SBo), for VIES
SOAP lookups on top of the built-in per-country checksum validation.

Ported from the SBo python2-vatnumber template: same upstream version
(1.2), same source. Upstream's setup.py still passes the removed
distutils/setuptools option use_2to3=True; the SlackBuild strips it
with a one-line sed patch since the code is already py2/py3-compatible
as-is.