Transfer tokens through contract - receives from sender and sends back to sender
Parameters:
Example: Transfer 1 XLM (10000000 stroops) from sender through contract back to sender
fn transfer(
env: soroban_sdk::Env,
sender: soroban_sdk::Address,
token: soroban_sdk::Address,
amount: i128,
) -> Result<(), ContractError>
Get the balance of an address for a specific token Useful for checking balances before/after transfer
fn get_balance(
env: soroban_sdk::Env,
address: soroban_sdk::Address,
token: soroban_sdk::Address,
) -> i128