Making the axum extractor more idiomatic

[si14]

I noticed that the current axum extractor diverges from the official Query design: https://docs.rs/axum/0.6.13/src/axum/extract/query.rs.html#51-65

In particular, I think two things can be done to make it a bit more idiomatic:

• returning a custom Rejection, allowing users to either use the supplied error handler, or accept Result<QueryString<Foo>, QueryStringRejection> and deal with it in the handler
• exporting multiple distinct types for parsing type vs configuring it with a layer

What do you think of those changes? If you're happy with them, I might make a stab at a PR implementing that.

[pooyamb]

Hi @si14 ,

I agree with you on both points, For the custom rejection part, I personally prefer to just copy and modify axum's extractors, so I wasn't sure what was more idiomatic, and I gladly would accept a PR for it.

For the parsing method part, what names do you suggest for these new extractors?