Multiple issues with the homepage

After the recent upgrade, I have been able to witness the new homepage. There are four important things to fix:

• we should drop the "Your latest work requests" section, we only care about workflows now (!1966 (merged))
• the various list of workflows should only show root workflows (and not child workflows) (!1966 (merged))
• the statistics in the "Scopes and workspaces" should also only count root workflows (and not child workflows) (!1966 (merged))
• the "Your completed workflows" should also show (root) workflows that ended up as "Aborted" instead of only "Completed" (!1966 (merged))
  • The idea is that you should be able to lookup all the workflows that completed/failed recently (up to a certain limit if you have enough, otherwise the last 5 no matter what the delay)
  • Not sure if we need to rename the section due to this.
• "You are authenticated as ..." should only be displayed once. (!1965 (merged))

We should likely also deal with #879 (closed) because it feels really cluttered with the pagination and the sorting/filtering options.

The page is also quite slow to load. Hopefully it will be better with the combinations of the various fixes as it will look at fewer rows, but if not, we might want to diagnose this and maybe consider some caching for the statistics of "Scopes and workspaces". We can move that to another issue later if it turns out to still be an issue.