Add policy processed verification for NetworkPolicyEvaluation

[Dyanngg]

This PR adds a function to verify that all policies in the cluster has
been processed by the Antrea controller before running the
antctl query networkpolicyevaluation command.

[qiyueyao]

Looks nice to simplify and reuse NetworkPolicyReference!

[tnqn]

I'm trying to understand why this is needed and whether it really helps:

1. In theory, there is no good way to ensure everything in K8s apiserver has been realized by Antrea as we never know whether informer is in sync with apiserver. Even we don't consider apiserver, informer can keep changing after you get a snapshot, the policies in the snapshot being realized doesn't mean all policies have received by antrea have been realized.
2. Converting upstream policies to internal policies should be pretty fast, I would say there is no human-sensible interval between antrea-controller receives the policy and converts it. Does it affect anything without the check?

[luolanzone]

@Dyanngg could you resolve the code conflicts and check @tnqn 's comment? Let me know if this is a must-have or we can move it out of milestone 2.0, Thanks.

[luolanzone]

Hi @Dyanngg I will close this since you confirmed that this is no need anymore, please reopen if you plan to rework on this. Thanks.