Errors do not respect the June2018 specs

[bboure]

Since the June 2008 specs, Errors adds the extensions entry. It also discourages the usage of any other additional entries.

GraphQL services should not provide any additional entries to the error format since they could conflict with additional entries that may be added in future versions of this specification.

AppSync should honor those specs and drop the data, errorInfo and errorType entries from the errors. Instead, it should implement the extensions one.

$util.error should probably become $util.error(String) and $util.error(String, Object)

Where the first argument is the message string, and the second an optional extensions map.

[katzeforest]

Thanks for the feedback, I will +1 this to the team on your behalf. :)