Automatic merge from submit-queue (batch tested with PRs 58487, 63666). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
use subtest for table units (pkg/scheduler/factory)
**What this PR does / why we need it**: Update scheduler's unit table tests to use subtest
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
**Special notes for your reviewer**:
breaks up PR: https://github.com/kubernetes/kubernetes/pull/63281
/ref #63267
**Release note**:
```release-note
This PR will leverage subtests on the existing table tests for the scheduler units.
Some refactoring of error/status messages and functions to align with new approach.
```
Pods in scheduler cache contains both the scheduled pods and those not
scheduled yet in scheduling queue. This commit adds the second group of
pods into consideration while comparing the cache.
A debug tool that collects resources from api server and compares it
with the scheduler cache. It currently only compares the node list, but
it should be easy to extend. The compare is triggered by signal USER2,
by doing
kill -12 ${SCHED_PID}
The compare result goes to scheduler log.
Towards #60860
