Add UI option to export Upgrade Status results as CSV

Thanks @eelkeblok for taking up the torch!

I had occasion to use this for a 9.x -> 10.x upgrade, so I'm adding my tweaks as well. To summarize my commits:

• Merged the latest 4.x branch
• Adjustments to make the CSV export look more like the table data on the upgrade status UI

I've been looking at how to integrate this more seamlessly. There is also ✨ Add options to provide drush analyze output in JSON and CSV Needs review which adds JSON on the drush CLI (and a little script to further process it which we could also add to the module as an option). It has different logic from your setup and less involved in how it builds the data. I think a middle ground would be good as well as ideally as much code reuse as possible between the output formats IMHO.