Create helper to identify namespace for packages

Currently, all of our namespaces for packages are hard coded in Big Bang. In addition, a handful of namespace values are passed down to packages (e.g. istio-system). It is best practice (e.g. DRY) to have a helper script to identify the namespace instead of hard coding it.

This issue would require a helper script that would act as a lookup table for the package's namespace (ideally one define function with a variable passed in). In addition, all references to namespace would be replaced with the helper script.