standardize success response from auth/users on v13 and greater

[caphrim007]

v13 and greater requires that users on partitions be looked up by filtering.

Also, modifying will succeed if you specify the user without the partition, but will report an error.

{
  "code": 404,
  "message": "The configuration was updated successfully but could not be retrieved. The error is \"01020036:3: The requested user (asdasd) was not found.\".",
  "errorStack": [],
  "apiError": 3
}

the SDK should be able to handle this without exposing the user to it