WIP: Experiment working with VU Context to control the iteration lifecycle

[ankur22]

What?

This is WIP

Experiment working with VU Context to control the iteration lifecycle. This change doesn't affect the browser lifecycle which should still be handled by the event system. This avoids working with a new abort event.

Why?

The VU context is easier to work with then a potential new abort event since it was designed to to specifically control the lifecycle of the iteration.

Checklist

• [ ] I have performed a self-review of my code
• [ ] I have added tests for my changes
• [ ] I have commented on my code, particularly in hard-to-understand areas

Related PR(s)/Issue(s)

Updates: https://github.com/grafana/xk6-browser/issues/1410

[ankur22]

New PR with tested changes are in https://github.com/grafana/xk6-browser/pull/1420