Set up code linting tools

- use flake8 as the main linting tool with the following plug-ins:
  + flake8-annotations
  + flake8-bandit
  + flake8-black
  + flake8-broken-line
  + flake8-bugbear
  + flake8-commas
  + flake8-comprehensions
  + flake8-debugger
  + flake8-docstrings
  + flake8-eradicate
  + flake8-isort
  + flake8-quotes
  + flake8-string-format
  + flake8-pyproject
  + pep8-naming
  + pydoclint
- use mypy for static type checking
- use ruff for linting for future compatibility
- add nox session "lint" to run these tools
- add `ruff check --fix ...` in nox session "format"
- lint all source files => no errors found