[Enhancement]: Add Success Message and Form Validations to Appointment Form

[akshay0611]

Problem:
The current appointment form lacks proper validation and does not provide feedback to users after submission. This can lead to confusion about whether their submission was successful.

Proposed Solution:

• Add client-side form validations to ensure all fields are filled correctly.
• Display a success message after the form is submitted successfully.
• Clear the form fields after submission for a better user experience.

Expected Outcome:
An appointment form that provides clear feedback to users, ensures valid inputs, and confirms successful submissions.