reqwest was replaced with hyper and hyper-rustls within monero-serai due to
reqwest *solely* offering a connection pool API. In the process, it was
demonstrated how quickly we can achieve equivalent functionality to reqwest for
our use cases with a fraction of the code.
This adds our own reqwest alternative to the tree, applying it to both
bitcoin-serai and message-queue. By doing so, bitcoin-serai decreases its tree
by 21 packages and the processor by 18. Cargo.lock decreases by 8 dependencies,
solely adding simple-request. Notably removed is openssl-sys and openssl.
One noted decrease functionality is the requirement on the system having
installed CA certificates. While we could fallback to the rustls certificates
if the system doesn't have any, that's blocked by
https://github.com/rustls/hyper-rustls/pulls/228.
If a crate has std set, it should enable std for all dependencies in order to
let them properly select which algorithms to use. Some crates fallback to
slower/worse algorithms on no-std.
Also more aggressively sets default-features = false leading to a *10%*
reduction in the amount of crates coordinator builds.
Due to each service having multiple distinct clocks, we can't expect a stable
ordering except the ordering an intact message-queue provides. The messages
emitted should be consistent however, solely with unknown order, which is why
we can craft intents based on their contents (already implemented by
processor-messages).
This is intended to be a reliable transport between the processors and
coordinator. Since it'll be intranet only, it's written as never fail.
Primarily needs testing and a proper ID.