Update package install method + Lint

Feature 1 : Replace the setup.py by the pyproject.toml approach to install the current package.

Using pyproject.toml is currently the standard approach (here is a blog post explaining a bit about it).

Package installation is still triggered by pip install .. This should not have any impact elsewhere.

Resources used for this conversion:

• [https://packaging.python.org/en/latest/guides/writing-pyproject-toml/]
• [https://setuptools.pypa.io/en/latest/userguide/quickstart.html]

Feature 2 : add linting in CI