normalize aws and gcp scripts

[tkishel]

Description

With this commit, both the AWS and GCP scripts ...

Use similar output formatting Pass shellcheck testing Implement shellspec testing Document (in comments) spec testing and script usage Renames the spec test files to eliminate a redundancy

Motivation and Context

In addition, the AWS script ...

Correctly skips a member account when assume role fails (caused by a return in a function not resulting in a continue in a calling loop)

How Has This Been Tested?

Tested with ...

shellspec spec/resource-count-aws.sh shellspec spec/resource-count-gcp.sh

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes if appropriate.
• [x] All new and existing tests passed.

[tkishel]

Sorry for the knock on pull request: holiday project.