revlog: register changelogv2 C implementation in parsers
This allows Python code to make use of the C implementation of the changelogv2
base operations when the C extensions are enabled.
The `format_version` values are now shared between the C and Python sides,
avoiding an additional translation for the selection of the format version to
use.
Differential Revision: https://phab.mercurial-scm.org/D12179
[build-system]
requires = ["setuptools", "wheel"]
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true