[BUG] Error responses missing in API specs

[imvtsl]

What is the bug?

APIs in the specification show response for success scenario. Responses for error scenarios are not added.

How can one reproduce the bug?

Consider this API spec as an example. Response body is missing for error status codes like 4xx, 5xx, etc.

What is the expected behavior?

The spec should have error responses to improve usability of the APIs.

[dblock]

💯 error responses are totally missing in most places, they often have common definitions, too