Automatic merge from submit-queue

Cluster Verification Framework

I've spent the last few days looking at the general patterns of verification we have that we tend to reuse in the e2es.  Basically, we need 
 
- label filters
- forEach and WaitFor (where forEach doesn't necessarily waitFor anything).
- timeouts
- multiple phases (reusable definition of state)
- an extensible way to define cluster state that can evolve over time in a data object rather than as a set of parameters that have magic semantics

This PR 
- implements the abstract above functionality declaratively, and w/o hidden semantics.
- addresses the sprawling duplicate methods in #23540, so that we can phase out the wrapper methods and replace them with well defined, extensible semantics for cluster state.
- fixes the recently discovered #23730 issue (where kubectl.go is relying on examples.go, which is obviously wacky) by using the new framework to implement forEachPod in just a couple of lines and migrating the wrapper function into framework.go.

There is some cleanup to do here, but this is seemingly working for a couple of use cases that are important (spark,cassandra,...,kubectl) tests. - i played with a few different ideas and this wound up seeming to be the most natural implementation from a usability standpoint... 

in any case, just thought id push this up as a first iteration, open to feedback.

@kubernetes/sig-testing @timothysc