feat: support Gateway/Class

[oliverbaehler]

Describe the feature

Since Gateway API is on a stable API, we should consider adding control for the GatewayClasses to begin with.

What would the new user story look like?

How would the new interaction with Capsule look like? E.g.

1. What are the prerequisites for this?
2. Tenant owner creates a new Namespace
3. This is going to be attached to the Tenant
4. All the magic happens in the background

Feel free to add a diagram if that helps explain things.

Expected behavior

A clear and concise description of what you expect to happen.

[prometherion]

Gateway APIis an add-on containing API kinds

We can make it better, honestly, and support a variety of extended APIs: just thinking of Service Mesh ones (e.g. Istio), Capsule could lock some Tenants in using just a specific class.

We have a boundary with #51, and we should revamp this opportunity with VAP.

I think Capsule could be an easier way to orchestrate policies leveraging native Kubernetes tools and ecosystem.
I'm worried about the support compatibility matrix here since we would need +1.30, even tho VAP seems available as Alpha from 1.26 which is out of the current LTS.

We need a huge effort in designing the API as well as the use-cases, I'd be delighted if community could add their potential use cases here.