* End polymorphic response in goals create
Being part of the v3 spec, this isn't well
(or at all) supported by OpenAPI generators.
Always respond with `Goal.ListResponse`
* Implement `PUT /custom_props`
* Implement bulk `DELETE /goals`
* Expose API for (bulk-)disabling custom props
* Add controller typespecs
* Delegate list wrapping to `Plausible.API.*`