Hi,
I am using Refit a lot, and noticed a pattern in my libraries which I dislike:

1. Use Refit
2. Notice that exceptions need to be handled somewhat differently than Refits generic mechanism (e.g. instead of throwing a generic ApiException throw an UnauthorizedAccessException if the StatusCode is a 401 or 403).
3. Write a wrapper interface around refit to statisfy Add top-level API #2

While this is not a large amount of code, it is annoying to write.
Would it be possible to add some attributes to Refit which can be used to instpect a Response and transform it, if necessary?

e.g.

` [Post("/api/v1")]
[OnException(ExceptionHandlingMethod)]

Task CreateAsync([Header("Authorization")] string authorization, [Body] CreateModel);
`