Update package layout to PyAnsys guidelines

[jorgepiloto]

As with other projects in the PyAnsys ecosystem, the layout of this project should adapt to the general guidelines.

Low effort

• Enable Ruff rules
  • PyCodestyle
  • PyDocstyle
  • PyFlakes, see fix: pyflakes style #1953
  • Isort
  • PEP8-Naming
  • Flake9-use-pathlib, see maint: modifying files to conform with "PTH" ruff rule #1949
  • Flake8-todos

Intermediate effort

• Use a src/ layout. Just need to move the "ansys/" dir inside a "src/" one and fix some links to this new location: Use src/ dir #664

• Use a pyproject.toml and drop any setup.py or setup.cfg files.

• Rename /docs directory to /doc: Link issue here.

• Implement Tox for the project

  • Drop any patch scripts in favor of Tox

• Use sphinx-autoapi for generating the API reference, see doc: use sphinx-autoapi for API reference #1952

High effort

• Use containers from the GitHub Container Registry in the CI/CD
• Rename master branch to main
• Use semver tags

More about packaging guidelines in https://dev.docs.pyansys.com/packaging/structure.html.