Developer Portal and mock policy can only handle a few content types

Only most common content types can be rendered by the Developer Portal and mock policy (E.g. application/json).

Other content types will not be rendered, such as:

- application/problem+json;charset=utf-8
- application/json; charset=utf-8
- application/hal-forms+json; charset=utf-8

Developer Portal will render them as "object", mock policy will return empty response.

Due to this the developer does not see the real content type.

Will there be support for these CTs in the future?

Start by tracing how the Developer Portal renders response content types and how the mock policy selects its response handling for the listed media types. Reproduce the behavior with the three examples, then verify that each is rendered with its real content type and that the mock policy returns the expected response rather than an empty one.

Written by the indexing model from the issue text.