Updating to HTTP crate v1

[Thomasdezeeuw]

Apologies if this is not the right way to go about this for this crate.

I'm wondering if it's possible to update actix-http (3.7.0) and actix-router (0.5.3) to use v1 of the http crate as both are still on v0.2.

I don't know if that is considered a breaking change or not though.

[robjtede]

also see discussion in #3208

[robjtede]

I'm open to the idea of providing the necessary compatibility functions to convert to and from http v1 types behind a crate feature. I think that is the most helpful thing we can do at this stage.

We only use the actual primitives from that crate:

• StatusCode
• Method
• Uri
• HeaderName
• HeaderValue

As such, the conversion methods will be extremely trivial (as shown already by @asonix: #3208 (comment)) but good to have nonetheless.

None of the composite types like header maps or request/response structures are used.

[Thomasdezeeuw]

For our use case we like to remove http v0.2 entirely, but I understand that will require a breaking change (i.e. won't happen until v5).