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
Make unversioned.ListMeta implement List. Update all the *List types so they implement GetListMeta.
This helps avoid using reflection to get list information.
Remove all unnecessary boilerplate, move the interfaces to the right
places, and add a test that verifies that objects implement one, the
other, but never both.