When using the json output of the cli (`-format=json`), a successful
call to the controller API would place the HTTP status code in the JSON
as `status_code`. However, if there was an error from the API the status
code would be placed in the JSON as `status`. In order to be consistent,
this adds a `status_code` field to the error response case. For
backwards compatibility it still populates `status` in the error case.
This inconsistency was missed partially due to a bug in the CLI tests.
The assertion on status code was not valid and would always be
successful. Thus this also fixes the assertions and tests.