chore(format): apply isort rule, update default rules

[wpbonelli]

• extend default rules in pyproject.toml
• apply import sorting
• fix line lengths: demo what's needed to fully observe E501
  • flopy/version.py
  • update_version.py
  • flopy/utils/zonbud.py
• ignore other line length violations in comments for now

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 73.0%. Comparing base (aa9f410) to head (e2c4299).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #2137 +/- ## ======================================= Coverage 73.0% 73.0% ======================================= Files 260 260 Lines 59483 59483 ======================================= Hits 43482 43482 Misses 16001 16001 ``` | [Files](https://app.codecov.io/gh/modflowpy/flopy/pull/2137?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=modflowpy) | Coverage Δ | | |---|---|---| | [flopy/utils/modpathfile.py](https://app.codecov.io/gh/modflowpy/flopy/pull/2137?src=pr&el=tree&filepath=flopy%2Futils%2Fmodpathfile.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=modflowpy#diff-ZmxvcHkvdXRpbHMvbW9kcGF0aGZpbGUucHk=) | `88.4% <100.0%> (ø)` | | | [flopy/utils/particletrackfile.py](https://app.codecov.io/gh/modflowpy/flopy/pull/2137?src=pr&el=tree&filepath=flopy%2Futils%2Fparticletrackfile.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=modflowpy#diff-ZmxvcHkvdXRpbHMvcGFydGljbGV0cmFja2ZpbGUucHk=) | `96.0% <100.0%> (ø)` | | | [flopy/utils/zonbud.py](https://app.codecov.io/gh/modflowpy/flopy/pull/2137?src=pr&el=tree&filepath=flopy%2Futils%2Fzonbud.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=modflowpy#diff-ZmxvcHkvdXRpbHMvem9uYnVkLnB5) | `66.8% <ø> (ø)` | | | [flopy/version.py](https://app.codecov.io/gh/modflowpy/flopy/pull/2137?src=pr&el=tree&filepath=flopy%2Fversion.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=modflowpy#diff-ZmxvcHkvdmVyc2lvbi5weQ==) | `100.0% <ø> (ø)` | |