Migrate 25 crates to monorepo

itoa
percent-encoding
untrusted
arbitrary
nix
arc-swap
arrayvec
axum-core
bindgen-cli
cov-mark
equivalent
fixedbitset
foreign-types
foreign-types-shared
fxhash
http
hyper
kernlog
lazycell
libtest-mimic
libz-sys
merge
merge_derive
mls-rs
mls-rs-crypto-traits

Bug: http://b/339424309
Test: treehugger
Change-Id: I02696660785cf0f1a76b79a100bb966c4afc43b9