Azure: Rework test_py job to publish its wrapper script

Both to aide in debugging of any test.py issues as well as to make it
easier to split the current matrix in two, have a new job that creates
and publishes the current wrapper script we use for test.py jobs.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>