`skaffold verify` should use the `defaultNamespace` specified in `deploy` as it's own default namespace

[aaron-prindle]

Issue tracks the idea that skaffold verify should use the defaultNamespace specified in deploy as it's own default namespace. Currently skaffold verify deploys to default by default which is not expected for most users and leads to confusion, perms issues, etc.

Slack thread that brought up this issue w/ more context:
https://kubernetes.slack.com/archives/CABQMSZA6/p1680520998478329

[aaron-prindle]

For example:

a skaffold has verify stanza and the tests are test1, test2
Can inspect get back the results:
verify: test1, test2?

And if a skaffold has verify + customActions, we can inspect and get back teh results
verify: [test1, test2]
customActions: [customaction1, customAction2]