Mesh 3865 - Adding unique VS name for copy VS feature

[vinay-g]

Checklist

🚨 Please review this repository's contribution guidelines.

• [ ] I've read and agree to the project's contribution guidelines.
• [ ] I'm requesting to pull a topic/feature/bugfix branch.
• [ ] I checked that my code additions will pass code linting checks and unit tests.
• [ ] I updated unit and integration tests (if applicable).
• [ ] I'm ready to notify the team of this contribution.

Description

What does this change do and why?

This change makes sure that the virtual service that gets copied across different clusters does not get over-written. It assumes that the namespace-vsname combination is unique.

Thank you!