## Bug description

Creating a selector with an attribute isn't working at all.

`[data-attr="bla"]`

## Expected behavior

It should work

## How to reproduce

1. Create action
2. Add an attribute in the selector
3. 


## Additional context

The reason for this is that we store the attributes as `attr__data-attr` but we do not add `attr__` in the filtering. I am working on a solution.


#### *Thank you* for your bug report – we love squashing them!

posthog/test/test_event_model.py
Person.objects.create(distinct_ids=["whatever"], team=self.team)
        event1 = Event.objects.create(
            team=self.team,
            distinct_id="whatever",
            elements=[
                Element(tag_name="span", order=0),
                Element(tag_name="a", order=1, attributes={"data-id": "123"}),
            ],
        )
        event2 = Event.objects.create(
            team=self.team,
            distinct_id="whatever",
            elements=[Element(tag_name="button", order=0, attributes={"data-id": "123"})],
        )
        action1 = Action.objects.create(team=self.team)
        ActionStep.objects.create(action=action1, selector='a[data-id="123"]')
        action1.calculate_events()
        events = Event.objects.filter_by_action(action1)
        self.assertEqual(len(events), 1)
        self.assertEqual(events[0], event1)
    def test_filter_events_by_url(self):
        Person.objects.create(distinct_ids=["whatever"], team=self.team)
        action1 = Action.objects.create(team=self.team)
        ActionStep.objects.create(
            action=action1, url="https://posthog.com/feedback/123", url_matching=ActionStep.EXACT,
        )
        ActionStep.objects.create(action=action1, href="/a-url-2")