tests: show graph log before and after widening in more cases I'm about to make some changes to which revisions get sent during widening. Some more tests will make it clearer what changes. I've also switched to graph log so we easily notice if the graph shape changes. Differential Revision: https://phab.mercurial-scm.org/D7091

[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
| hgext/fsmonitor/pywatchman/
| contrib/python-zstandard/
| contrib/grey.py
'''
skip-string-normalization = true
quiet = true