The function calculateTotalPrice accepts an array of items
as input, where each item is represented as an object
with properties itemName, price, and discountPercentage.
The function should determine the total price of the items in the
shopping cart after applying any available discounts.
If the input array is empty, the function should return 0.
The formula to calculate the discounted price
is price - (price * (discountPercentage / 100)).