#5335 Allow user to manage the gateway tokens they want reported with balance command

Add a command gateway connector-tokens:

1. With no argument it displays the gateway tokens the user wants to report balances on
2. With an argument, select a connector_chain_network and give it a list of tokens whose balances you want to be able to query like DAI,USDC,WETH.

Link: https://github.com/hummingbot/hummingbot/pull/5335