Handle `JSON::Serializable` values within `Hash`/`NamedTuple` controller action return types

[Blacksmoke16]

• Was incorrectly choosing Athena::Serializer for JSON::Serializable types nested within a hash/named tuple resulting in the value being null
  • NOTE: Only 1 level deep of the hash/nt value type is checked. I.e. Hash(String, Hash(String, SomeJsonType)) would not work. Nested array values are supported however