Given a string of CSV data containing a list of transactions:

    1. Parse the CSV data into an array of "transaction" objects

    2. Print the name of each unique currency in the data set (e.g. "ETH, BTC")

    3. For each currency, print the currency and value of the transaction with the largest positive value for that currency (e.g. "ETH: 0.519, BTC: 1.137")

    This exercise covers materials from the sections: types, syntax, standard library, functions.