## 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
from typing import Dict, List, Optional, Union
from rest_framework import status
from posthog.api.property_definition import PropertyDefinitionQuerySerializer
from posthog.models import EventDefinition, EventProperty, Organization, PropertyDefinition, Team
from posthog.test.base import APIBaseTest, BaseTest
class TestPropertyDefinitionAPI(APIBaseTest):
    EXPECTED_PROPERTY_DEFINITIONS: List[Dict[str, Union[str, Optional[int], bool]]] = [
        {"name": "$browser", "query_usage_30_day": None, "is_numerical": False},
        {"name": "$current_url", "query_usage_30_day": 3, "is_numerical": False},
        {"name": "is_first_movie", "query_usage_30_day": None, "is_numerical": False},
        {"name": "app_rating", "query_usage_30_day": 1, "is_numerical": True},
        {"name": "plan", "query_usage_30_day": 1, "is_numerical": False},
        {"name": "purchase", "query_usage_30_day": None, "is_numerical": True},
        {"name": "purchase_value", "query_usage_30_day": None, "is_numerical": True},
        {"name": "first_visit", "query_usage_30_day": None, "is_numerical": False},
    ]
    def setUp(self) -> None: