Support type annotations

[bkeryan]

Python 3 supports optional type annotations using the typing module.

Benefits of specifying type annotations:

• Clients can use external tools like mypy to perform static type-checking.
• Editors such as Visual Studio Code use type annotations to provide auto-complete suggestions.

nidaqmx-python already documents types in docstrings, so the information is already there. It would only need to be output in a different format.