fix: namespaced agent events with agent prefix

[exu]

Pull request description

Control Plane and Agent are on same events prefix - some edge cases (like recent invalid NATS selector settings caused strange events ping pongs. to allow even use single NATS for On prem setup I've changed prefix to agent in agent

Checklist (choose whats happened)

• [ ] breaking change! (describe)
• [ ] tested locally
• [ ] tested on cluster
• [ ] added new dependencies
• [ ] updated the docs
• [ ] added a test

Breaking changes

Changes

Fixes