#[RestRoute]
Attribute on methods, repeatable.
Registers a public method of a #[RestController] service as a REST route.
The route is the controller's base path followed by $path. {name}
placeholders match the method parameter of the same name. Parameters typed
with a service candidate are injected, a WP_REST_Request parameter receives
the request, all other parameters are request arguments of the same name;
their schema is derived from the parameter type, default value and #[Param].
A method returning void responds with 204 No Content.