Attributes on inferred type

[Lege19]

I have found these related issues/pull requests

Would be enabled by #4114

Description

At the moment the types inferred by query! and similar derive Debug and nothing else. I'm writing a server with Axum and I often need a query type to implement serde::Deserialize so that it can be sent as JSON to the client. Currently this requires using query_as! and writing out all the fields twice.

Prefered solution

Allow users to specify extra attributes to be applied to the inferred type.

I've suggested a specific syntax for this as part of #4114.

Is this a breaking change? Why or why not?

This is not a breaking change because the existing macros are not effected.