Rename squatted crates (#1241)

* Rename squatted crates

This commit adds the staging- prefix to squatted crates so we can go forward and publish them to crates.io.

Using the staging- prefix is a temp fix until we decide on replacement names.
https://forum.parity.io/t/renaming-squated-crates-in-substrate-polkadot-cumulus/1964/6

* Fix test after crate renames

* Update Lockfile