Add shell script to gather log data via SSM

[dav3r]

🗣 Description

This PR adds an "extras" directory containing a shell script that can be used to fetch the ClamAV scan log data from a list of AWS EC2 instances via SSM.

💭 Motivation and context

This addresses the issue raised in #30. I will leave it up to discussion whether or not this PR is enough for us to close out #30.

🧪 Testing

I ran the script several times and verified that it worked as expected. I also tested the script with no arguments and with -h and with --help and confirmed that the usage text was displayed as intended.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.
• All new and existing tests pass.

✅ Pre-merge checklist

• Finalize version.

✅ Post-merge checklist

• Create a release.

[mcdonnnj]

Seems like a reasonable path to provide this functionality. I will say, for the sake of discussion, that I don't think this resolves #30 as I would like native support in the package. We may want to explore offerings like community.aws.aws_ssm connection to support this kind of connectivity natively.

[dav3r]

I will say, for the sake of discussion, that I don't think this resolves #30 as I would like native support in the package. We may want to explore offerings like community.aws.aws_ssm connection to support this kind of connectivity natively.

I'm fine with leaving #30 open. For what it's worth, I played around with community.aws.aws_ssm connection in the past and couldn't get it to work as I had hoped here, but it looks like there have been some updates since then. I updated the description in #30 to mention community.aws.aws_ssm connection in the "Implementation notes" section.

PS: I believe the issue was that community.aws.aws_ssm connection did not allow me to supply the --parameters data when attempting to start an SSM session.