[meta] Metrics for CI reports

[tylersmalley]

Over the past year, the time and size of our builds have drastically increased. I feel that providing a comment on the PR with details of the build we could help curtail this. Additionally, I find myself constantly checking to see if the build has completed. If Jenkins posted a comment it would have the added benefit of notification on build/test completion.

Here are some ideas:

• Build size compared to upstream
• Warn if large files were added
• Build time compared to upstream average
• Addition of duplicate dependencies
• Change in code coverage
• Change in dependencies (including nested dependencies)
• Saved Objects field count
• The failure! We shouldn't have to dig through Jenkins Console.

Related: #5800

[kimjoar]

So many +1s to this. More tooling will make it way more obvious when we're introducing problems. Right now it's way too difficult to see that you're introducing a duplicate dependency or increasing the build with 0.5MB.

[epixa]

+100

[LeeDr]

I filed an issue to get client side code coverage metrics #22221