Verify NKG against community conformance tests

[f5yacobucci]

The Gateway community maintains a set of conformance tests to inform users and implementations. As a first step in improving NKG compliance and quality, we need to verify our implementation for common expectations and begin automating our usage of these tests.

See here: https://gateway-api.sigs.k8s.io/concepts/conformance/

Due to the early nature of NKG's implementation, we may need to target tests to specific areas and work towards running a complete set.

### Tasks
- [ ] #370
- [ ] #369
- [ ] #368
- [ ] #634
- [ ] #610
- [ ] #611
- [ ] https://github.com/nginxinc/nginx-kubernetes-gateway/issues/648
- [ ] https://github.com/nginxinc/nginx-kubernetes-gateway/issues/644

A/C:

• Run conformance tests and propose a realistic set to build upon.
• File tickets for features we do support that fail tests.
• Build a pipeline to automate conformance test runs. Make sure there's at least one test enabled and passing

[kate-osborn]

I found some blockers to running the conformance tests against NKG: #370 #369 #368

[kate-osborn]

This issue is blocked by #508