title: Associate a subscription to personal entity in Stripe portal
body: <p>I want to use Stripe portal to manage subscriptions. In my app, an ENTITY is linked to a SUBSCRIPTION.</p>
  <p>So a USER can have several ENTITY and subscribe one SUBSCRIPTION for each ENITTY.</p>
  <p>My problem is that when a user manage several SUBSCRIPTION in the stripe portal. There is no distinction between Stripe subscriptions. So I want to distinguish them by :</p>
  <ul>
  <li>adding a custom name for each property (for example the ENTITY NAME) but can't find any way to do this</li>
  <li>adding a metadata to the subscription but I can't find any way to display meta data in Stripe</li>
  </ul>
  <p>Is there any solution to distinguish several subscriptions ?</p>