Merge pull request #37643 from ncdc/informer-gen

Automatic merge from submit-queue (batch tested with PRs 35300, 36709, 37643, 37813, 37697)

Add generated informers

Add informer-gen and the informers it generates. We'll do follow-up PRs to convert everything currently using the hand-written informers to the generated ones.

TODO:

- [x] switch to `GroupVersionResource`
- [x] finish godoc

@deads2k @caesarxuchao @sttts @liggitt

hack/verify-flags/known-flags.txt

@@ -280,6 +280,7 @@ insecure-port
 insecure-skip-tls-verify
 instance-metadata
 instance-name-prefix
+internal-clientset-package
 iptables-drop-bit
 iptables-masquerade-bit
 iptables-min-sync-period
@@ -351,6 +352,7 @@ leader-elect-retry-period
 lease-duration
 leave-stdin-open
 limit-bytes
+listers-package
 load-balancer-ip
 lock-file
 log-flush-frequency
@@ -596,6 +598,7 @@ use-kubernetes-cluster-service
 use-kubernetes-version
 user-whitelist
 verify-only
+versioned-clientset-package
 viper-config
 volume-dir
 volume-plugin-dir