Hyper 1.0 support

[davidpdrsn]

Hyper is aiming to ship 1.0 this year and in the process making a lot of changes to the public API which will impact axum. We can discuss the changes here.

Off the top of my head the biggest changes will probably be

• Hyper dropping tower::Service support since tower-service wont be 1.0 in time.
• Moving hyper::Server into hyper-util. I don't think we should have a public dependency on hyper-util since breaking releases would cascade into axum.
• Removing hyper::Body (or possibly moving it into hyper-util). I think we should consider giving axum-core its own body type. Relevant to https://github.com/tokio-rs/axum/issues/1110

I haven't thought much about this yet but once 0.6.0 is out we start that work.

Relevant links

• Hyper 1.0 project board
• Hyper's roadmap

[genusistimelord]

I guess the newer FromRequestParts and IntoResponseParts functions and State help Cover the loss of tower::Service. But this will heavily affect every single layer-based library when and if you do update to the newest Hyper. So maybe we can improve and prepare all the Parts changes to make migration easier later. I am willing to switch my libraries over to using them so they can be used as Examples for other library makers to change theirs over too.

I'm guess hyper-util will be a faster change with more API breaking branch?

I think Axum should also have its own Body type. This would make it easier to Abstract the Body from different source's and allow you more flexibility over them.