Add basic serializer for form response to api [SCI-11533]

app/controllers/api/v1/steps_controller.rb

@@ -92,7 +92,7 @@ module Api
       end
 
       def permitted_includes
-        %w(tables assets checklists checklists.checklist_items comments user)
+        %w(tables assets checklists checklists.checklist_items comments user form_responses)
       end
 
       def check_manage_permissions

app/serializers/api/v1/form_response_serializer.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module Api
+  module V1
+    class FormResponseSerializer < ActiveModel::Serializer
+      type :form_responses
+      attributes :id, :form_id, :position
+
+      include TimestampableModel
+
+      def position
+        object&.step_orderable_element&.position
+      end
+    end
+  end
+end

app/serializers/api/v1/step_orderable_element_serializer.rb

@@ -13,6 +13,8 @@ module Api
           TableSerializer.new(object.orderable.table).as_json
         when 'StepText'
           StepTextSerializer.new(object.orderable).as_json
+        when 'FromResponse'
+          FormResponseSerializer.new(object.orderable).as_json
         end
       end
     end

app/serializers/api/v1/step_serializer.rb

@@ -17,6 +17,7 @@ module Api
       has_many :tables, serializer: TableSerializer
       has_many :step_texts, serializer: StepTextSerializer
       has_many :step_comments, key: :comments, serializer: CommentSerializer
+      has_many :form_responses, serializer: FormResponseSerializer
       has_many :step_orderable_elements, key: :step_elements, serializer: StepOrderableElementSerializer
 
       include TimestampableModel

app/serializers/api/v2/step_serializer.rb

@@ -17,6 +17,7 @@ module Api
       has_many :tables, serializer: Api::V1::TableSerializer
       has_many :step_texts, serializer: Api::V1::StepTextSerializer
       has_many :step_comments, key: :comments, serializer: Api::V1::CommentSerializer
+      has_many :form_responses, serializer: Api::V1::FormResponseSerializer
       has_many :step_orderable_elements, key: :step_elements, serializer: Api::V1::StepOrderableElementSerializer
 
       include TimestampableModel