More robust windows sysprep procedure

[andrey-malets]

Windows sometimes fails sysprep stage, now it leads to abandoned snapshot volume and failed sysprep procedure, which must be recovered manually. We should

1. Cleanup failed snapshot after waiting for sysprep
2. Make a couple more attempts to start sysprep process with a fresh snapshot.
3. Write a message to the log for each attempt and end up in consistent state if all attempts fail, rolling back the whole process so previous snapshot can be used as if nothing happened.