Address issues destroying VPC with Terraform

[tpdownes]

Address Terraform destroy issues by advising manual deletion of resources with links to the Google Cloud Console.

Submission Checklist

• Have you installed and run this change against pre-commit? pre-commit install
• Are all tests passing? make tests
• If applicable, have you written additional unit tests to cover this
  change?
• Is unit test coverage still above 80%?
• Have you updated any application documentation such as READMEs and user
  guides?
• Have you followed the guidelines in our Contributing document?

[mittz]

Thank you Tom for making the simpler and clearer solution note to address the issue without risks by terraform import. LGTM!