fix: handling of attribute with array type in middleware for field function

[jichon]

Contributor checklist

In a simple data layer, a resource with an array-type attribute does not properly set the middleware fields correctly. i.e.,

attribute :results, {:array, UnionType} do
  ....
end

• Bug fixes include regression tests
• Chores
• Documentation changes
• Features include unit/acceptance tests
• Refactoring
• Update dependencies

[zachdaniel]

🚀 Thank you for your contribution! 🚀