Automatic merge from submit-queue
Move the remaining controllers to shared informers
Completes work done in 1.6 to move the last two hold outs to shared informers - tokens controller and scheduler. Adds a few more tools to allow informer reuse (like filtering the informer, or maintaining a mutation cache).
The mutation cache is identical to #45838 and will be removed when that merges
@ncdc @deads2k extracted from openshift/origin#14086
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