<!-- PR description-->
New commands to initialize & connect to a repo on local or network attached storage.
* `repo init filesystem --path /tmp/repo`
* `repo connect filesystem --path /tmp/repo`
Includes basic unit & e2e tests. More coverage to be added in a following PR to keep the size contained.
**Updates:**
* Added Repo path sanitization i.e. handle relative paths, make paths cross platform compatible, etc.
* Removed retention artifacts, not supported for filesystem storage.
* cli docs - auto updated.
* Manually tested with all corso backup/restore/export commands.
**Doesn't include**
1. Symlinks
2. User ids wiring into repo.
3. Repos documentation update - in an upcoming PR.
4. Prefix support -> kopia doesn't support prefixes for `filesystem` storage
5. More E2E tests.
---
#### 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
<!--- Please check the type of change your PR introduces: --->
- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup
#### Issue(s)
<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->
* #1416
#### Test Plan
<!-- How will this be tested prior to merging.-->
- [x] 💪 Manual
- [x] ⚡ Unit test
- [x] 💚 E2E
