Move negative check for testing "not patched" output to test-cmd-util.sh
as exiting with code 1 was causing patch_test.go to fail when the error
was expected as part of the test.
This fixes#38779.
This allows us to avoid case in which printers.GetStandardPrinter
returns nil for both printer and err removing any potential panics that
may arise throughout kubectl commands.
Please see #38779 and #38112 for complete context.
Add comment explaining adding handlers to printers.HumanReadablePrinter
also remove an unnecessary conversion of printers.HumanReadablePrinter
to printers.ResourcePrinter.
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