## Description
Pull code specific to making snapshots in kopia into a separate file. Factor out code specific to handling collections in preparation for having to deal with kopia items as well during incremental backups. Apart from code movement and factoring into functions no other changes have been made
Viewing by commit will make changes easier to see
## Type of change
- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [x] 🐹 Trivial/Minor
## Issue(s)
* #1740
## Test Plan
- [ ] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E
