Move monero-serai to simple-request

Deduplicates code across the entire repo, letting us make improvements in a
single place.

Cargo.lock

@@ -4877,8 +4877,6 @@ dependencies = [
  "group",
  "hex",
  "hex-literal",
- "hyper",
- "hyper-rustls",
  "modular-frost",
  "monero-generators",
  "multiexp",
@@ -4890,6 +4888,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha3",
+ "simple-request",
  "std-shims",
  "subtle",
  "thiserror",