Add scheduled statuses (#9706)

Fix #340

config/routes.rb

@@ -283,6 +283,7 @@ Rails.application.routes.draw do
       resources :streaming, only: [:index]
       resources :custom_emojis, only: [:index]
       resources :suggestions, only: [:index, :destroy]
+      resources :scheduled_statuses, only: [:index, :show, :update, :destroy]
 
       resources :conversations, only: [:index, :destroy] do
         member do