Appease Clippy 1.68 and refactor http_api (#4068)

## Proposed Changes

Two tiny updates to satisfy Clippy 1.68

Plus refactoring of the `http_api` into less complex types so the compiler can chew and digest them more easily.

Co-authored-by: Michael Sproul <michael@sigmaprime.io>

consensus/types/src/lib.rs

@@ -1,6 +1,4 @@
 //! Ethereum 2.0 types
-// Required for big type-level numbers
-#![recursion_limit = "128"]
 // Clippy lint set up
 #![cfg_attr(
     not(test),