feat: Add CSAT response APIs (#2503)

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

spec/builders/csat_surveys/response_builder_spec.rb

@@ -0,0 +1,30 @@
+require 'rails_helper'
+
+describe ::CsatSurveys::ResponseBuilder do
+  let(:message) do
+    create(
+      :message, content_type: :input_csat,
+                content_attributes: { 'submitted_values': { 'csat_survey_response': { 'rating': 5, 'feedback_message': 'hello' } } }
+    )
+  end
+
+  describe '#perform' do
+    it 'creates a new csat survey response' do
+      csat_survey_response = described_class.new(
+        message: message
+      ).perform
+
+      expect(csat_survey_response.valid?).to eq(true)
+    end
+
+    it 'updates the value of csat survey response if response already exists' do
+      existing_survey_response = create(:csat_survey_response, message: message)
+      csat_survey_response = described_class.new(
+        message: message
+      ).perform
+
+      expect(csat_survey_response.id).to eq(existing_survey_response.id)
+      expect(csat_survey_response.rating).to eq(5)
+    end
+  end
+end