[Chronik] Upgrade to axum 0.7

Summary:
It's good to keep up with development, and this version will use the recently 1.0 stabilized crates for http and hyper.

Axum 0.7 changes quite a few things, but luckily for us it's impact is limited to only a few files.

The upgrade guide for axum 0.7 can be found here: https://tokio.rs/blog/2023-11-27-announcing-axum-0-7-0

This version also makes it convenient to use our own custom std::net::TcpListener, which allows us to use SO_REUSEADDR.

Test Plan: ninja check-functional

Reviewers: Fabien, #bitcoin_abc

Reviewed By: Fabien, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D15486