Re-add accessors for singular answer cases

Otherwise rendering fails

app/models/answer.rb

@@ -1,6 +1,8 @@
 class Answer < ApplicationRecord
   extend Answer::TimelineMethods
 
+  attr_accessor :has_reacted, :is_subscribed
+
   belongs_to :user, counter_cache: :answered_count
   belongs_to :question, counter_cache: :answer_count
   has_many :comments, dependent: :destroy