Background:

A local veterinary clinic has asked you to develop a simple management system to track their patients $($pets$),$ pet owners, and appointments. The system should leverage object$-$oriented programming principles to ensure modularity, reusability, and scalability.

Requirements:

Classes and Objects:

Pet: This class should have member variables to store the pet's name, age, type $($e$.$g$.,$ dog, cat, bird$),$ and a unique ID$.$ Include methods that allow you to get and set these properties.

Owner: This class should include details about the pet owner such as name, contact number, and address. It should also have a method to display owner details.

Appointment: This class represents an appointment and should include details like appointment ID$,$ date, time, and a reference to the associated Pet and Owner.

Inheritance:

Create a subclass of Pet for different types of pets, adding specific attributes or methods that are unique to each type. For example, a Dog class might have a method bark$().$

Polymorphism:

Implement a virtual function in the Pet class that is overridden in each subclass to display the sound that the pet makes, such as meow$()$ for a cat and chirp$()$ for a bird.

Encapsulation:

Ensure all data members of the classes are inaccessible directly and must be accessed through getter and setter methods.

Associations:

Each Appointment object should correctly reference its associated Pet and Owner objects.

Input$/$Output:

Write a main function to create objects of Pet, Owner, and Appointment. Your program should allow users to input details for each object and then display a summary of upcoming appointments, including details of the pet, owner, and appointment.