Add helper functions and tests that find
old assist bases and add them to the set
of backups to garbage collect. This
allows us to remove backups that aren't
displayed to the user because they had
some errors during them
The more recent assist backups can still
be used for incremental backups so we
don't want to garbage collect all of
them
This still does not wire this code into
any existing corso function, just adds
additional cleanup logic
---
#### Does this PR need a docs update or release note?
- [ ] ✅ Yes, it's included
- [x] 🕐 Yes, but in a later PR
- [ ] ⛔ No
#### Type of change
- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup
#### Issue(s)
* #3217
#### Test Plan
- [ ] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E
24b9831ce6