Smoke Test Pipeline Metrics should compare against last release sizes

[michael-hawker]

@azchohfi Hmm, was just messing with the DownloadPipelineArtifact wondering if we published it as an Artifact if we could use the specific flag to somehow grab the latest pipeline artifact from the main branch? Not sure if we can get that specific with the project guid? runVersion latestFromBranch maybe? 🤔 That looks promising. I can try it out later once I get the base script running.

Ref: https://docs.microsoft.com/en-us/azure/devops/pipelines/tasks/utility/download-pipeline-artifact?view=azure-devops

Originally posted by @michael-hawker in #3600 (comment)

• The current script should save it's results to a file for that pipeline in DevOps
• Before the script runs the data for the last release branch (or main to start) should be fetched
• The script needs to take that data file as a potential input
• If it has input, it needs to also compare each project against the last size for that project
• If there's a change above ~15kb(TBD?), a new dependency, or a new binary, it should post a comment to the PR with a message/details of change

[michael-hawker]

We should also investigate the retention policy on the DevOps and figure out how to ensure we retain artifacts for our rel/* branches if we start comparing against those. For a first pass of this comparing against main is acceptable as we'll be auditing it moving forward.