feat: more Gateway API kind wrappers

[KevFan]

Description

Closes: https://github.com/Kuadrant/policy-machinery/issues/11

• Adds wrappers the the following so they can be used in the topology as targetable / object / policy:

  • gateway.networking.k8s.io/v1

  • GRPCRoute (targetable)

  • gateway.networking.k8s.io/v1beta1

  • ReferenceGrant (object)

  • gateway.networking.k8s.io/v1alpha3

  • BackendTLSPolicy (policy)

  • gateway.networking.k8s.io/v1alpha2

  • TCPRoute (targetable)

  • TLSRoute (targetable)

  • UDPRoute (targetable)

  • BackendLBPolicy (policy)

  • v1 (core)

  • Namespace (targetable)

• Additionally adds the LinkFunc's for the new xRoute kinds from above as part of the Gateway API Topology

  • These were not added to controller/topology_builder for now, unless we want to enable these already as part of the controller package?
  • The link function for Namespace as a targetable in the topolgy was not added as part of this PR as this seems not as straightforward which might require some deeper considerations such as:
    • Will Namespace be also a parent to Gateway since Gateway is namespace scoped? (i.e. Gateway will have both GatewayClass and Namespace as parents ). Who will take precedence in this case?
    • Namespace can be a parent of whatever the resource in its namespace which are also targetable, does this matter? i.e. a Route in a namespace may not have a Gateway since a Route can use a Gateway from a different namespace as a parent reference

[KevFan]

There seems to a failing unit test that I'll look into, for some reason the same test is passing locally but failing on the CI now 🤷

[KevFan]

Still looking into the unit test failure, it's failing locally for me now. Seems to an issue that surfaced after the new dot engine PR was merged. Service -> ServicePort is linked multiple times now on the graph for some reason 🤔