Add create-backup and restore-from-backup commands to MariaDB-Monitor

Add manual commands to create a backup from a server and restoring a server from a backup. The backups are stored on a remote server. The ip of the remote server and the storage directory must be given in MaxScale configuration.

Original description:

It would be extremely helpful to be able to manage and configure backups through MaxScale. User could determine the storage location and frequency of backup. Even include an interface that listed successful backups and alerted on failed backups.

Could roll this into a backup/restore component to automatically rebuild a slave down the line as well.