[Feature] Email collect message hooks (#331)

- Add email collect hook on creating conversation
- Merge contact if it already exist

spec/services/message_templates/hook_execution_service_spec.rb

@@ -0,0 +1,20 @@
+require 'rails_helper'
+
+describe ::MessageTemplates::HookExecutionService do
+  context 'when it is a first message from web widget' do
+    it 'calls ::MessageTemplates::Template::EmailCollect' do
+      message = create(:message)
+      # this hook will only get executed for conversations with out any template messages
+      message.conversation.messages.template.destroy_all
+
+      email_collect_service = double
+      allow(::MessageTemplates::Template::EmailCollect).to receive(:new).and_return(email_collect_service)
+      allow(email_collect_service).to receive(:perform).and_return(true)
+
+      described_class.new(message: message).perform
+
+      expect(::MessageTemplates::Template::EmailCollect).to have_received(:new).with(conversation: message.conversation)
+      expect(email_collect_service).to have_received(:perform)
+    end
+  end
+end