Let's build a simple coffee shop simulation.

Your task is to implement the sellCoffee() function in the CoffeeShop class. This function should create a new CoffeeCup, set its attributes, and serve the coffee using the Kotlin apply() scope function.

• The CoffeeShop class has to be defined using the sellCoffee() method.
• The sellCoffee() method should accept a clientName and coffeeType.
• In the sellCoffee() function create a CoffeeCup instance and initialize its attributes (clientName, coffeeType, isServed).
• Use the apply() scope function to set the properties of CoffeeCup and call the serveCoffee method.
• Return the initialized CoffeeCup.

• The CoffeeCup class should represent a cup of coffee with attributes like clientName, coffeeType, and isServed.
• The CoffeeShop class should have a sellCoffee() method, which creates a CoffeeCup, sets its attributes, and serves it.