feat: Ensuring all images in Package are from registry1

Pointing to the IronBank equivalents for "jettech/kube-webhook-certgen", "bats/bats", & "bitnami/kubectl"

The latter 2 images don't seem to ever be used in various stages of testing package, but better safe than sorry.

closes https://repo1.dso.mil/platform-one/big-bang/bigbang/-/issues/164