Move error response creation into a role (and use vnd.err or similar format)

[timbunce]

Currently the error response is ad-hoc an JSON data structure. It would be good to adopt a more formal standard such as application/vnd.error+json.

It would also be good to move the error response creation into a role so people can replace it with whatever they need.

[timbunce]

An alternative to vnd.err is the Collection+JSON error object

[ungrim97]

I suspect that Collection+JSON error would be better as I forsee a distinct likelyhood that we will add support for Collection+JSON format types anyway

Does JSON API not provide an error format?

[timbunce]

Another alternative is HTTP Problem.

[timbunce]

JSON API has discussed this topic several times!