Remove helper that returned a polymorphic path

This is similar to what we did in commits 1a902a967 and fa3781059.

app/components/shared/recommended_index_component.html.erb

@@ -19,7 +19,7 @@
       <% recommended.each do |recommended| %>
         <div class="small-12 medium-6 large-4 column end">
           <div class="recommendation" data-equalizer-watch>
-            <h3><%= link_to recommended.title, recommended_path(recommended) %></h3>
+            <h3><%= link_to recommended.title, polymorphic_path(recommended) %></h3>
           </div>
         </div>
       <% end %>

app/components/shared/recommended_index_component.rb

@@ -1,6 +1,6 @@
 class Shared::RecommendedIndexComponent < ApplicationComponent
   attr_reader :recommended, :disable_recommendations_path, :namespace
-  use_helpers :recommended_path, :current_path_with_query_params
+  use_helpers :current_path_with_query_params
 
   def initialize(recommended, disable_recommendations_path:, namespace:)
     @recommended = recommended

app/helpers/welcome_helper.rb

@@ -7,17 +7,6 @@ module WelcomeHelper
     "display: none;" if index.positive?
   end
 
-  def recommended_path(recommended)
-    case recommended.class.name
-    when "Debate"
-      debate_path(recommended)
-    when "Proposal"
-      proposal_path(recommended)
-    else
-      "#"
-    end
-  end
-
   def render_recommendation_image(recommended)
     image_path = calculate_image_path(recommended)
     image_tag(image_path) if image_path.present?

app/views/welcome/_recommended_carousel.html.erb

@@ -13,7 +13,7 @@
               <div class="card">
                 <%= render_recommendation_image(recommended) %>
                 <div class="card-section">
-                  <%= link_to recommended_path(recommended) do %>
+                  <%= link_to polymorphic_path(recommended) do %>
                     <h4 class="truncate-horizontal-text"><%= recommended.title %></h4>
                   <% end %>
                   <%= wysiwyg(recommended.description) %>