Set ResolvedRef Condition to True in HTTPRoute status when all references are resolved

[pleshakov]

Gateway API prescribes setting ResolvedRef condition
https://github.com/kubernetes-sigs/gateway-api/blob/c67f3fd31976ea74ea06a78c2a88ae38df95a41d/apis/v1beta1/shared_types.go#L255-L290

NKG already implements it -- https://github.com/nginxinc/nginx-kubernetes-gateway/blob/f74c06ded5c3d647b0909fe542f3e70dbc96774c/internal/state/conditions/conditions.go#L253-L295 -- however, only when references are not resolved.

Implement the happy path case when references are resolved.

Also, conformance tests require it. Example: https://github.com/kubernetes-sigs/gateway-api/blob/6efcfdf8aff7aa7c3ed8deb956e5b93eed779234/conformance/tests/httproute-matching.go#L46

Acceptance criteria:

• Set ResolvedRef Condition to True in HTTPRoute status when all references are resolved
• Update docs https://github.com/nginxinc/nginx-kubernetes-gateway/blob/main/docs/gateway-api-compatibility.md#httproute

[mpstefan]

Additional A/C: Include InvalidListener, UnsupportedValue, and any other undocumented reasons in condition status.