Fixed an issue that occurred when the storage is a database

[Superredstone]

Using a custom storage like the following Python does not call the setter method, not saving anything inside the database

class DbStorage(BaseStorage):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        session = self.get_session()
        if not WizardStep.objects.filter(session=session).exists():
            self.init_data()

    def get_session(self): 
        return Session.objects.get(session_key=self.request.session.session_key)

    def get_db_safe(self) -> OnboardingWizardStep:
        defaults = {"payload": {'step': None, 'step_data': {}, 'step_files': {}, 'extra_data': {}}}
        s, _ = WizardStep.objects.get_or_create(session=self.get_session(), defaults=defaults)
        return s

    @property
    def data(self):
        return self.get_db_safe().payload

    @data.setter
    def data(self, value):
        s = self.get_db_safe()
        s.payload = value
        s.save()

The following two functions inside wizard/storage/base.py without a temporary value do not allow for saving

    def _get_current_step(self):
        return self.data[self.step_key]

    def _set_current_step(self, step):
        self.data[self.step_key] = step