Add a recovery test: reusing an old synced folder

Scenario:

1. Add a new account using the foo folder.
2. Remove the account, keep the foo folder as-is.
3. Remove xattrs using the clean-folder CLI argument.
4. Re-add the account using the foo folder.

The goal is to check that local data is not re-downloaded at all. Drive should simply recreate the database and check the all files are there.