Begin work on combining affected and fixed by packages #1287

[johnmhoran]

Reference: #1287

[TG1999]

@johnmhoran is this PR ready for review ?

[johnmhoran]

Thanks for the question @TG1999. No, this draft PR is nowhere close to being ready for review. I started this work on the VCIO Vulnerability UI/API back in October when my Package UI/API PR was ready and awaiting comments, but this work incorporates that work and thus I hit a roadblock early on and stopped because the Package PR lingered for a while. That roadblock is now gone. ;-)

This Vulnerability work also involves the "bad" data issues (e.g., duplicate PURLs), since combining the affected by tab and fixed by tab will currently include all the duplicate PURLs (and might also involve their respective but possibly different vulnerabilities). However, I'm inclined to go ahead despite the data issue and see what the combined affected by/fixed by tabs look like. I expect that for each set of duplicate PURLs we'll have 2 rows, not 1, which might confuse or even put off users but seems unavoidable while the data issue persists.