Chopsticks tests so ensure it actually works

[xlc]

I am evaluating if we can use asset-transfer-api but it is missing some important items and the most important one is:

• What are the supported use cases? Where are the tests to ensure it actually works and stay working in future?

For reference, this is the bridge sdk we are currently using https://github.com/polkawallet-io/bridge
Here are the supported chains and assets https://github.com/polkawallet-io/bridge/blob/master/docs/support-bridges.md
And some tests to ensure it works and detects compatibility issue in the case a parachain made breaking change upgrade https://github.com/AcalaNetwork/e2e-tests/tree/master/tests/bridge-sdk

I suggest integrating asset-transfer-api to the polkadot-ecosystem-tests that we are working on so that it can be used to ensure the sdk actually works.