## Is your feature request related to a problem?

As a team accumulates data, they will have events/properties that are no longer in use that clutter their app.

Example from our team:
![image](https://user-images.githubusercontent.com/148820/143202334-42d73ab6-13be-4661-ba7a-83c86788b9e8.png)


## Describe the solution you'd like

Under event/properties stats allow 'hiding' events/properties from view.

## Describe alternatives you've considered

Alternatively, go the route of "verified" events/properties (as He@p) does - show those first. See also https://help.heap.io/category/heap-administration/data-governance/

## Additional context

Note: Existing reports, etc should still work well even with 'removed' events/properties.

Related: https://github.com/PostHog/posthog/issues/7126

#### *Thank you* for your feature request – we love each and every one!

posthog/api/test/test_property_definition.py
response = self.client.get(f"/api/projects/{self.team.pk}/property_definitions")
        self.assertEqual(response.status_code, status.HTTP_200_OK)
        response_data = response.json()
        assert sorted([r["name"] for r in response_data["results"]]) == [
            "$browser",
            "$current_url",
            "app_rating",
            "first_visit",
            "is_first_movie",
            "plan",
            "purchase",
            "purchase_value",
        ]
        
        response = self.client.get(f"/api/projects/{self.team.pk}/property_definitions/?search=firs")
        self.assertEqual(response.status_code, status.HTTP_200_OK)
        response_data = response.json()
        assert [r["name"] for r in response_data["results"]] == ["first_visit", "is_first_movie"]
        
        response = self.client.get(f"/api/projects/{self.team.pk}/property_definitions/?search=p ting")
        self.assertEqual(response.status_code, status.HTTP_200_OK)
        self.assertEqual(response.json()["count"], 1)
        self.assertEqual(response.json()["results"][0]["is_seen_on_filtered_events"], None)
        for item in response.json()["results"]:
            self.assertIn(item["name"], ["app_rating"])
        
        response = self.client.get(f"/api/projects/{self.team.pk}/property_definitions/?search=%24cur")
        self.assertEqual(response.status_code, status.HTTP_200_OK)