[backup] add errorType to error logs in backup
Summary:
Add errorTypes to errors logs in backup service.
This includes:
- DDB Error
- Auth Error
- Blob Error
- WS Error
Depends on D13941
Test Plan: Deployed to staging. Verified that JSON error logs on cloudwatch include errorType
Reviewers: kamil, bartek
Reviewed By: kamil, bartek
Subscribers: ashoat, tomek
Differential Revision: https://phab.comm.dev/D13942