Automatic merge from submit-queue (batch tested with PRs 50254, 50174, 50179)

Moved node/testutil to upper dir.

**What this PR does / why we need it**:
Moved node/testutil to upper directory (`pkg/controller`); it's used by several controllers, and we need to test some helper func in `pkg/controller`.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: part of #49522

**Release note**:

```release-note
N/A
```