Adds missing API features to the index and show endpoints

The tests were not properly testing all the features and this
resolves issues found

app/helpers/spree/api/api_helpers_decorator.rb

@@ -3,10 +3,19 @@
 Spree::Api::ApiHelpers.module_eval do
   @@review_attributes = [
     :id, :product_id, :name, :location, :rating, :title, :review, :approved,
-    :created_at, :updated_at, :user_id, :ip_address, :locale, :show_identifier
+    :created_at, :updated_at, :user_id, :ip_address, :locale, :show_identifier,
+    :verified_purchaser
+  ]
+
+  @@feedback_review_attributes = [
+    :id, :user_id, :review_id, :rating, :comment, :created_at, :updated_at, :locale
   ]
 
   def review_attributes
     @@review_attributes
   end
+
+  def feedback_review_attributes
+    @@feedback_review_attributes
+  end
 end

app/views/spree/api/reviews/_feedback_review.json.jbuilder

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+json.cache! [I18n.locale, feedback_review] do
+  json.(feedback_review, *feedback_review_attributes)
+end

app/views/spree/api/reviews/_review.json.jbuilder

@@ -5,4 +5,7 @@ json.cache! [I18n.locale, review] do
   json.images(review.images) do |image|
     json.partial!("spree/api/images/image", image: image)
   end
+  json.feedback_reviews(review.feedback_reviews) do |feedback_review|
+    json.partial!("spree/api/reviews/feedback_review", feedback_review: feedback_review)
+  end
 end

spec/controllers/spree/api/reviews_controller_spec.rb

@@ -34,10 +34,13 @@
         it 'returns all approved reviews for the product' do
           review.update(approved: true)
           review.images << create(:image)
+          review.feedback_reviews << create(:feedback_review, review: review)
           expect(Spree::Review.count).to be >= 2
           expect(subject.size).to eq(2)
           expect(subject["reviews"][0]["id"]).to eq(review.id)
           expect(subject["reviews"][0]["images"].count).to eq(1)
+          expect(subject["reviews"][0]["feedback_reviews"].count).to eq(1)
+          expect(subject["reviews"][0]["verified_purchaser"]).to eq(false)
           expect(subject["avg_rating"]).to eq("5.0")
         end
       end