Support for returning relay encoded id when subscribing to destroy events

[mike1o1]

Closes #306

Currently, if attempting to subscribe to a destroy event, the message that is received has the shape of something like:

"myResource": {
  "destroyed": "{myUUID}"
}

However, if a user has a schema with relay_ids?: true, this is the wrong type of ID, as it doesn't get encoded as a relay id.

This PR addresses that by passing the relay_ids? value down through the domains and resources, and eventually to the resolve/2 function which gets added to the Absinthe middleware. When encoding the id for a :destroy action, the relay_ids? setting will now be respected.

---

Tests

I couldn't find a way to change the relay_ids? value at runtime during the test, so this unfortunately requires setting up a whole new RelaySchema and associated RelayDomain and RelaySubscribable resource. While verbose, this seemed like the most straight forward way to keep existing tests and schema in place.

Contributor checklist

• Bug fixes include regression tests
• Features include unit/acceptance tests

[zachdaniel]

Looks like some credo errors to fix.

[zachdaniel]

🚀 Thank you for your contribution! 🚀