Need to activate (Status enable) a gift card only when the payment is confirmed

Can we merge this with the dev branch?

Makes sense to me, but should please be reviewed by the community!

Please don't add unrelated changes / fixes. That makes review harder and is confusing. Thanks!

The MR is not applying to 2.0.0-alpha2

I've fixed some merge conflicts.

I've also created a patch that works for version 2.0.0-alpha2

In #16 I accidentally left out the GiftcardActivatedEvent class so I've re-uploaded the patch in #17

Just another patch to fix the exception: TypeError: Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher::dispatch(): Argument #1 ($event) must be of type object, string given

I'm sorry for spamming this issue queue. I've made some modifications to the patch for 2.0.0-alpha2 to make sure it provides the same functionality as the merge request does.