This query represents a user's choice to allow or deny access to "powerful features" of the platform, as specified in the [Permissions
W3C Specification](https://w3c.
github.io/permissions/).
When signalled by the WebView through the `query-permission-state` signal, the
application has to eventually respond, via `webkit_permission_state_query_finish()`, whether it grants, denies or requests a dedicated
permission prompt for the given query.
When a PermissionStateQuery is not handled by the user, the user-agent is instructed to `prompt` the user for
the given permission.