Code Cleanup: Usage of Polymorphic User instead of ExternalUser and InternalUser

Renamed requestor_user_id -> user_id
Index of request_for_comments now returns the n (5?) newest requests per user. Solved via sliding windows in postgres, code added to model.
Added route to /my_request_for_comments/ that shows all requests for the current user.
Changed view from ERB to slim

config/routes.rb

@@ -2,6 +2,7 @@ FILENAME_REGEXP = /[\w\.]+/ unless Kernel.const_defined?(:FILENAME_REGEXP)
 
 Rails.application.routes.draw do
   resources :request_for_comments
+    get '/my_request_for_comments', as: 'my_request_for_comments', to: 'request_for_comments#get_my_comment_requests'
   resources :comments, except: [:destroy] do
     collection do
       delete :destroy