[4pt] Impliment methods for music album and genres

[Joel-100]

• Add_item method in the genres 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 Music album class

  should override the method from the parent class
  should return true if parent's method returns true OR if cover_state equals to "bad"
  otherwise, it should return false