Pytest-harvest

The `fixture_store` fixture, provided by the plugin, does not have `autouse=True` anymore. Fixed [20](https://github.com/smarie/python-pytest-harvest/issues/20).

`get_all_pytest_fixture_names` now returns fixtures that are indirectly parametrized, as well as fixtures that are not parametrized. Fixed [19](https://github.com/smarie/python-pytest-harvest/issues/19).

See [documentation page](https://smarie.github.io/python-pytest-harvest/changelog/) for details.

Now raising a better exception if `saved_fixture` is used on session- or module-scope fixtures. Fixes [18](https://github.com/smarie/python-pytest-harvest/issues/18)

See [documentation page](https://smarie.github.io/python-pytest-harvest/changelog/) for details.

Another import error was causing results bag to be saved incorrectly in presence of steps.

See [documentation page](https://smarie.github.io/python-pytest-harvest/changelog/) for details.

Results bags are now compliant with `pytest-steps`: there are now one per step. This fixed [16](https://github.com/smarie/python-pytest-harvest/issues/16).

See [documentation page](https://smarie.github.io/python-pytest-harvest/changelog/) for details.

Integrating `pytest-steps` in default fixtures seemed like a bad idea because it led to automatic behaviour that could silently raise warnings. Let `pytest-steps` handle it on its side.

See [documentation page](https://smarie.github.io/python-pytest-harvest/changelog/) for details.

Default fixtures `module_results_df` and `session_results_df` now automatically become multi-level indexed when pytest steps is installed and there are steps in the tests.

See [documentation page](https://smarie.github.io/python-pytest-harvest/changelog/) for details.