gcloud core/client landing zone shadowing - for hybrid, triage or day 2 deployments

see terraform shadow in #870
see kcc automation #766
see hybrid #818
branch https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/tree/gh824-gcloud
org clouddevopsdev

There is a requirement for a mixed day 2 deployment strategy around kubernetes and gcloud or terraform.
The following packages will shadow the existing kubernetes yaml config - but in gcloud

- [core-landing-zone - inventory](https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/tree/main/solutions/core-landing-zone#resources)
- [client-setup - inventory](https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/blob/main/solutions/client-setup/README.md#resources)
-[ client-landing-zone - inventory](https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/blob/main/solutions/client-landing-zone/README.md#resources)
- [client-project-setup](https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/blob/main/solutions/client-project-setup/README.md#resources)
- gatekeeper-policies - optional https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/tree/main/solutions/gatekeeper-policies
- project/hub-env - optional for non-firewall-plus https://cloud.google.com/blog/products/identity-security/introducing-google-cloud-firewall-plus-with-intrusion-prevention IaaS security via Fortinet https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/blob/main/solutions/project/hub-env/README.md#resources

see
```mermaid
graph LR;
style LZV2 fill:#44f,stroke:#f66,stroke-width:2px,color:#fff,stroke-dasharray: 5 5
%% mapped and documented
project/hub-env-->core-landing-zone;
client-setup;
client-setup-->dns-project;
client-setup-->kcc-management-project;
client-landing-zone-->client-setup;
client-project-setup-->client-landing-zone;
client-project-setup-->client-management-project;
gatekeeper-policies;

kcc-management-project;
core-landing-zone-->kcc-management-project;
dns-project-->core-landing-zone;
logging-project-->core-landing-zone;
client-management-project-->client-setup;
host-project-->client-landing-zone;

```
[mermaid - diagrams as code](https://mermaid-js.github.io/mermaid/#/flowchart?id=graph)

```
gcloud compute ssh $(whoami) --zone $ZONE
```