Multi token

https://eips.ethereum.org/EIPS/eip-1155

🏗️ Building

cargo b -p "multi-token*"

✅ Testing

Run all tests, except gclient ones:

cargo t -p "multi-token*" -- --skip gclient

Run all tests:

# Download the node binary.
cargo xtask node
cargo t -p "multi-token*"