Add organization-id as an auto-setter

[morgante]

Packages using org-level functionality often depend on knowing the organization ID. We should add organization ID as an autosetter (similar to project ID), which can be retrieved from the current gcloud context.

The org ID for the active project can be retrieved with this command: gcloud projects get-ancestors $(gcloud config get-value core/project) --format='get(id)' | tail -1

Suggested name: gcloud.core.organization-id

[mikebz]

I am curious about these things being auto-setters. Seems like this is a GCP specific feature and as such might be best reserved for functions that a GCP specific functions rather than something being built into kpt core? @frankfarzan

[morgante]

Two challenges with doing them as functions:

1. Functions inside a container don't have access to the gcloud environment.
2. Functions would need to be manually invoked, so it's not automatic/zero-friction

That being said, I think it is worth thinking about how autosetters could be done more extensibly.