Delete attribute should support the POST HTTP method

[shochdoerfer]

Resource bundle version affected: v1.12.0

Description
While experimenting with Sylius Stack, I realized that the Delete attribute in the resource bundle exposes the route only for the DELETE HTTP method.

The Bootstrap Admin UI templates include a form with the POST method for deleting entries, see here. Thus, by default I am not able to delete resources via the UI. Unless I patch the code or manually add the route myself.

Possible Solution
While I understand why the attributes follow the HTTP standards and work as they work, I think it makes sense to extend the Delete attribute with an additional flag also to expose the POST route. Thus the attribute would by default follow the HTTP standards but could be configured also to expose a POST route if needed.