tests/python: add local copy of typing module

tests/python: add local copy of typing module

Add a local copy of the typing module [1], in order to be able to use
the typing module features with Python 3.4.

Add notes about the license in the top-level LICENSE file.

Add exclusions to avoid this file being reformatted by black, analyzed
by flake8 and its imports sorted by isort.

Add the tests/utils/python/utils.py with an import
er files will be able to use the
typing module using:

    typing = utils._typing_mod

... and not care where the typing module comes from.

[1] https://raw.githubusercontent.com/python/typing/3.10.0.2/src/typing.py

Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I7648e700f7e350acc595004c697a89e1fc97de4a
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/10892
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>