[2pt] Implement methods: Add Item & Can be Archived - Student 2

[RaoAkif]

• Implement methods:
  • add_item method in the Genre class
    • should take an instance of the Item class as an input
    • should add the input item to the collection of items
    • should add self as a property of the item object (by using the correct setter from the item object)
  • can_be_archived?() in the MusicAlbum class
    • should override the method from the parent class
    • should return true if parent's method returns true AND if on_spotify equals true
    • otherwise, it should return false