## 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/property_definition.py
"""
    The raw query is used to both query and count these results
    """
    team_id: int
    table: str
    property_definition_fields: str
    limit: int
    offset: int
    should_join_event_property: bool = True
    name_filter: str = ""
    numerical_filter: str = ""
    search_query: str = ""
    event_property_filter: str = ""
    event_name_filter: str = ""
    is_feature_flag_filter: str = ""
    excluded_properties_filter: str = ""
    event_property_join_type: str = ""
    event_property_field: str = "NULL"
    
    event_name_join_filter: str = ""
    posthog_eventproperty_table_join_alias = "check_for_matching_event_property"
    params: Dict = dataclasses.field(default_factory=dict)
    def with_properties_to_filter(self, properties_to_filter: Optional[str]) -> "QueryContext":