[Feature] Email collect message hooks (#331)

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

app/javascript/widget/api/contact.js

@@ -0,0 +1,10 @@
+import authEndPoint from 'widget/api/endPoints';
+import { API } from 'widget/helpers/axios';
+
+export const updateContact = async ({ messageId, email }) => {
+  const urlData = authEndPoint.updateContact(messageId);
+  const result = await API.patch(urlData.url, {
+    contact: { email },
+  });
+  return result;
+};