Enable the new Backup Packages job

Backups are now stored in the following file name pattern: "[Id]/[Version]/[Hash].nupkg" (to avoid confusion of "." usage and make it possible to parse out those values WITHOUT opening the NuPkg). Also, they are stored in a separate storage account, alongside database and warehouse backups.

File backups are performed every 10 minutes, but use a "state file" (stored in Blob Storage) which records the last seen Package Key in order to incrementally update the backup. Every day the state file is wiped and all files are re-checked (not re-copied, just checked against their hashes)