Cannot create image from last full backup when source is another instance

[blitzmann]

We have a production server called PROD01. It stores backups in it's local B:\ drive. When creating an image using the following command (using a production database and using the dev server as the restore surrogate)

New-DcnImage -SourceSqlInstance PROD01 -DestinationSqlInstance DEV01 -ImageNetworkPath \\dev01\g$\dbaclone-images\ -Database MyDatabase -UseLastFullBackup

This fails with a data access error

$lastFullBackup = Get-DbaDbBackupHistory -SqlInstance $SourceSqlInstance -SqlCredential $SourceSqlCredential -Database $db.Name -LastFull

This is the line that ultimately is the culprit. It's due to the fact that this reports the backup file in relation to the source server, so eg B:\SQL\Full\MyDatabase.bak. The dev server doesn't have this path (more specifically, this runs local to the script location, not the destination sql host, so if running locally on my machine, if I don't have B drive with this path, this will still fail, regardless of if the dev instance has access to it)

I have a solution that will replace B:\SQL\Full\MyDatabase.bak with UNC admin path \\PROD01\B$\SQL\Full\MyDatabase.bak. This works for our case specifically, but I'm not too familiar with the nuances of using the admin paths and drive$. I think ideally, the backup drives would be on a share, and we should replace the local drive letter with whatever that share is (although I'm not sure if it's possible to do that programmatically without giving the command specific locations)

I can submit a PR for my fix as a stop gap until someone can work out a more permanent solution

[blitzmann]

I forgot to link the PR! /o\

This was merged with #194 :D