New decorator `pytest_fixture_plus` allows to use several `pytest.mark.parametrize` on a fixture. Therefore one can use multiple `cases_data` decorators, too. Fixes [19](https://github.com/smarie/python-pytest-cases/issues/19).
*Note: this is a temporary feature, that will be removed if/when [pytest supports it](https://github.com/pytest-dev/pytest/issues/3960).*
See [documentation page](https://smarie.github.io/python-pytest-cases/changelog/) for details.