Automatic merge from submit-queue

Move the common test functions from cmd_test.go to cmd/testing/fake.go

**What this PR does / why we need it**:
This is so that we can use NewAPIFactory() from cmd/set/*test.go
Up until now we would get a import loop error.

This commit also adds a basic unit test case for cmd/set/set_image.go

**Which issue this PR fixes**
partial #34592

**Special notes for your reviewer**:
None

**Release note**:
```release-note
NONE
```