normalizeErrorResponse should do less

Our original intention with normalizeErrorResponse was to provide a standard way of presenting error responses. To achieve this goal we detected different scenarios and coerced the errors into JSONAPI format. normalizeErrorResponse is now quite unpredictable, especially to new users.

To goal is to reduce the amount of work that normalizeErrorResponse does to allow users to opt-in to formatting their error response instead of doing it manually.

TODO

• Add a deprecation warning to normalizeErrorResponse stating that current behavior of normalizeErrorResponse is deprecated and will be removed in Ember Ajax 3.0
• Refactor Error Classes to ES6 and add errors getter that throws a deprecation warning that errors property will be removed in Ember Ajax 3.0
• Copy the payload onto payload property of error instance

Related Issues

• https://github.com/ember-cli/ember-ajax/issues/157

[jherdman]

Ah, yes! That worked like a charm. #til

[alexlafroscia]

Closed by #265