Handle 409, `ErrorFolderExists` error in restore path while creating destination calendar. We need to fix this for all m365 services. This PR is focused on calendar only.
Context:
`CreateCalendar()` may fail with ErrorFolderExists under certain error conditions. For e.g. consider below scenario.
1. `CreateCalendar()` does a POST to graph to create restore destination calendar but this fails with 5xx.
2. It's possible that step 1 may have left some dirty state in graph. For e.g. it's possible that the destination folder in step 1 was actually created, but 5xx was returned due to other reasons.
3. So when we reattempt POST in such a scenario, we sometimes observe ErrorFolderExists error .
4. Corso should be resilient to such errors. To fix this, when we encounter such an error, we will do a GET to fetch the restore destination folder and add it to folder cache.
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#### Does this PR need a docs update or release note?
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- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No
#### Type of change
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- [x] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup
#### Issue(s)
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#### Test Plan
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Integration tests and mock tests will be added in a follow up PR.
- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E
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