cbbackupmgr: logging to stdout should also log to the log file

Problem
Logging to STDOUT does not log to the log files.

Currently in Cloud we have to choose between logging to stdout or logging to a file. Being able to do both would provide a dual benefit in that we can troubleshoot using a log collection tool for backup jobs but also retain logs for the customer in their backup storage. We do not have access to those logs without customer intervention and by having the stdout we would remove the need to contact a customer.

Expectation
Logging should always happen to the files

Set a stdout flag to add that functionality without removing the ability to still use the log file.