This completes the wiring for Exchange preview backups. A few notable
points:
* Adds new config substruct(?) for limits on items/data
* Adds "reasonable defaults" (very small) for Exchange data categories
* Adds "important" and "skip" containers for Exchange data categories
All the above can be tweaked as we determine what values work best
Manually tested
1. regular backup
2. preview backup
3. regular backup
Verified that no merge base is used for the preview backup and the
merge base made in (1) is used for the backup in (3)
This feature is not exposed via CLI
May be easiest to review by commit
---
#### Does this PR need a docs update or release note?
- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No
#### Type of change
- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup
#### Issues
Merge after:
* #4657
* #4607
#### Test Plan
- [x] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E