Revert "[8.x] Fix attributes returning a collection instead of an array (#654)"

This reverts commit 9a6a3d5.

Author: duncanmcclean

src/Http/Controllers/CP/Traits/ExtractsFromModelFields.php

@@ -17,7 +17,7 @@ protected function extractFromFields(Model $model, Resource $resource, Blueprint
         $fields = $blueprint
             ->fields()
             ->setParent($model)
-            ->addValues($values->toArray())
+            ->addValues($values->all())
             ->preProcess();
 
         $values = $fields->values()->merge([