Transfers a specified amount from one account to another.
Examples
account1 <- BankAccount("ACC123", "John Doe", 1000)
account2 <- BankAccount("ACC456", "Jane Smith", 500)
transfer(account1, account2, 200)
#> Transferred $200.00 from ACC123 to ACC456
#> ACC123 new balance: $800.00
#> ACC456 new balance: $700.00