- If sync fails we set authFailedAt
- This information is displayed in the frontend in accounts with a `Sync
Failed` pill
- The user can reconnect his account in the dropdown menu
- A new OAuth flow is triggered
- The account is synced
* rename database services to repository
* refactor more repositories
* more refactoring
* followup
* remove unused imports
* fix
* fix
* Fix calendar listener being called when flag is off
* remove folders
