Allows us to finally remove the old `serai-dex/substrate` repository _and_
should have CI pass without issue on `develop` again.
The changes made here should be trivial and maintain all prior
behavior/functionality. The most notable are to `chain_spec.rs`, in order to
still use a SCALE-encoded `GenesisConfig` (avoiding `serde_json`).
* Rename the coins folder to networks
Ethereum isn't a coin. It's a network.
Resolves#357.
* More renames of coins -> networks in orchestration
* Correct paths in tests/
* cargo fmt
