Extract methods in ballot component

Assigning variables in the view makes the code harder to read.

app/components/budgets/ballot/ballot_component.html.erb

@@ -15,7 +15,6 @@
 </header>
 
 <div class="row ballot">
-  <% ballot_groups = ballot.groups.sort_by_name %>
   <% ballot_groups.each do |group| %>
     <% heading = ballot.heading_for_group(group) %>
     <div id="<%= dom_id(group) %>" class="small-12 medium-6 column end">
@@ -46,7 +45,6 @@
     </div>
   <% end %>
 
-  <% no_balloted_groups = budget.groups.sort_by_name - ballot_groups %>
   <% no_balloted_groups.each do |group| %>
     <div id="<%= dom_id(group) %>" class="small-12 medium-6 column end">
       <div class="margin-top ballot-content">

app/components/budgets/ballot/ballot_component.rb

@@ -8,4 +8,14 @@ class Budgets::Ballot::BallotComponent < ApplicationComponent
   def budget
     ballot.budget
   end
+
+  private
+
+    def ballot_groups
+      ballot.groups.sort_by_name
+    end
+
+    def no_balloted_groups
+      budget.groups.sort_by_name - ballot.groups
+    end
 end