Icu 5232 credential mirage mocks (#1204)

* feat: 🎸 Add mirage mocks for credential

✅ Closes: ICU-5232

* chore: 🤖 Update Credential Store factory to handle credentials

✅ Closes: ICU-5232

* feat: 🎸 Added mirage mocks for credential

✅ Closes: ICU-5232

Co-authored-by: Cameron Perera <cameron.perera@hashicorp.com>

addons/api/mirage/models/credential.js

@@ -0,0 +1,7 @@
+import { belongsTo } from 'ember-cli-mirage';
+import Model from './base';
+
+export default Model.extend({
+  scope: belongsTo(),
+  credentialStore: belongsTo(),
+});