Use map for scan results

[ccampo133]

Description of the change

Use a map (keyed by ARN) for scan results instead of a slice. This ensures that duplicate scan results are avoided (e.g. if the same DynamoDB table is reported on multiple regional scans).

Type of change

• Bug fix (non-breaking change that fixes an issue).
• New feature (non-breaking change that adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklists

Development

• Lint rules pass locally.
• The code changed/added as part of this pull request has been covered with tests.
• All tests related to the changed code pass.

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached.
• Jira issue referenced in commit message and/or PR title.

Testing

Unit tests.

[yoursnerdly]

LGTM