Updated route.ts

[krishnendu-2003]

Problem

I have made all the necessary changes as was supposed to be made as per the contribution ts/js code.

Summary of Changes

1. Wrapped the main logic inside try/catch to make sure consistent error handling.
2. Removed throw with throw new Error() for better consistency in error messages.
3. Removed @ts-ignore
4. Redefined the logic for next and prev navigation items with slice() and find() for better and efficient navigation
5. Strengthened type safety by adding more checks to avoid potential null or undefined issues, ensuring smoother runtime operations.

Fixes #

1. Updated the error handling logic as needed to work with Error instances rather than error strings.
2. Adjusted the code to handle null and undefined values as per the new type safety rules.