Add Error Handling for Non-Existent Ticket IDs in Ticket Page

[AyushDharDubey]

Description:
Currently, the TicketPage doesn't properly handle the case when the id provided does not exist in the system. If the ID doesn't correspond to an existing ticket, the page crashes unexpectedly.

Expected Behavior:

• If the id does not correspond to any ticket, the user should see a clear error message like "Ticket not found" or be redirected to a custom 404 page.
• The getTicketById function should handle invalid cases gracefully by returning a null or some indication when the ticket is not found, avoiding any crashes or undefined states.

Steps to Reproduce:

1. Attempt to access TicketPage with an invalid ticket ID (for eg. try hitting http://localhost:3000/TicketPage/invalid-ticket-id).
2. Observe that the app breaks.

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We need to make sure the getTicketById function correctly handles failure scenarios, including cases where the API does not return a valid ticket, and shows appropriate feedback on the page.

[MadhavDhall]

Kindly assign this issue to me
My approach:
if getTicketById does not return the desired object then not-found page's component appears.