feat: Add SNS topic delivery status IAM role

[chris3ware]

Description

The purpose of this pull request is to add delivery status logging for the SNS topic. This is achieved by specifying an IAM role with permission to write to CloudWatch logs. If a role is not specified, then a role will be created - if delivery logging is required.

Motivation and Context

I recently worked on a project which required compliance with NCSC Operational Best Practices. SNS delivery status logging must be enabled to comply with this framework. I created the topic outside of the module initially, but thought it would be a useful addition to the module.

Breaking Changes

How Has This Been Tested?

• :white_check_mark: I have updated at least one of the examples/* to demonstrate and validate my change(s)
• :white_check_mark: I have tested and validated these changes using one or more of the provided examples/* projects

• :white_check_mark: I have executed pre-commit run -a on my pull request