Add preview of followers removed in domain block modal in web UI (#32032)

config/routes/api.rb

@@ -125,6 +125,10 @@ namespace :api, format: false do
       get :search, to: 'search#index'
     end
 
+    namespace :domain_blocks do
+      resource :preview, only: [:show]
+    end
+
     resource :domain_blocks, only: [:show, :create, :destroy]
 
     resource :directory, only: [:show]