Fix sidekiq web UI

Connects to sul-dlss/dor-services-app#2638

This PR follows the instructions from the Sidekiq docs: https://github.com/mperham/sidekiq/wiki/Monitoring#rails-api-application-session-configuration

config/application.rb

@@ -51,5 +51,9 @@ class Application < Rails::Application
 
     # turn off drawing of Active Storage's default routes, we'll add the ones we want
     config.active_storage.draw_routes = false
+
+    # Set up a session store so we can access the Sidekiq Web UI
+    # See: https://github.com/mperham/sidekiq/wiki/Monitoring#rails-api-application-session-configuration
+    config.session_store :cookie_store, key: '_sdr-api_session'
   end
 end

config/routes.rb

@@ -2,6 +2,11 @@
 
 require 'sidekiq/web'
 
+# From Sidekiq docs: https://github.com/mperham/sidekiq/wiki/Monitoring#rails-api-application-session-configuration
+# Configure Sidekiq-specific session middleware
+Sidekiq::Web.use ActionDispatch::Cookies
+Sidekiq::Web.use Rails.application.config.session_store, Rails.application.config.session_options
+
 Rails.application.routes.draw do
   scope 'v1' do
     post '/auth/login', to: 'authentication#login'