ni-python-styleguide's `--extend-exclude` format is inconsistent with `black`

[bkeryan]

Some of our projects attempt to exclude the same files in both tools.black and tools.ni-python-styleguide. However, the extend_exclude key has a different format for each tool: black uses a regex and ni-python-styleguide uses a comma-separated list of fnmatch patterns.

In nidaqmx-python, we tried to keep these in sync, but copying the ni-python-styleguide format to the tools.black section results in a regex that doesn't match anything.
https://github.com/ni/nidaqmx-python/blob/master/pyproject.toml#L82

[mshafer-NI]

To add some more flavor,

because we have flake8-black in play, anyone running "black ." may have files get formatted that ni-python-styleguide would ignore if they don't configure black.

Workarounds:

• provide extend_exclude to both tools, in seperate formats
• only ever run ni-python-styleguide fix and NOT call black directly.