WIP: Add Reasons to Block and Test Results

[corbob]

PR Summary

Add Reasons to block and test results. Allowing for providing a reason when skipping a block with -Skip, or seeing the reported reason when using Set-ItResult.

Fixes #2049

PR Checklist

• PR has meaningful title
• Summary describes changes
• PR is ready to be merged
  • If not, use the arrow next to Create Pull Request to mark it as a draft. PR can be marked Ready for review when it's ready.
• Tests are added/update (if required)
• Documentation is updated/added (if required)

Corbob's checklist of known things before ready

• Commit messages are not at all descriptive.
• Includes extra files that were used during testing.
• Does not work correctly for all XML outputs.
• Possibly needs tests?
• Need to at least document how I've tested it.