In vision samples add error check, since the error isn't thrown by default

[nnegrey]

PR this first came up: #2569

Perform an error check on all sample code for something like this:

error {
  code: 3
  message: "The URL does not appear to be accessible by us. Please double check or download the content and pass it in."
}

Then republish docs

[nnegrey]

Another interesting note, not all methods have an error, they just return no results.

[nnegrey]

Methods that have no error:

1. object_localization - (beta and GA)

Methods that will throw an error:

1. batch_annotate_files (beta)