Automate group creation

[obriensystems]

• see https://cloud.google.com/sdk/gcloud/reference/identity/groups/create
• see https://registry.terraform.io/modules/terraform-google-modules/group/google/latest
• see kcc https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/blob/main/solutions/guardrails/configs/iam/group-iam.yaml
• associate 2 or more users across the groups
• see https://github.com/CloudLandingZone/accelerators_accelerateurs-gcp/blob/main/deployment-templates/Terraform/guardrails/1-guardrails/iam.tf#L37

see shadow https://github.com/GoogleCloudPlatform/pbmm-on-gcp-onboarding/issues/271

[obriensystems]

automate via terraform defined in https://github.com/GoogleCloudPlatform/pbmm-on-gcp-onboarding/issues/271#issuecomment-1661425718