Use SMO Default File location with the FileRelocator

[Kaneraz]

While we typically have a homogeneous environment with all our SQL Servers at the same version, the directory where the data files are stored reflects the original version installed on the machine. I'd rather assume that the files should be stored in the default directory on each destination server than in a specific location. This will require some change to how the current FileRelocator works though because it relocates to the same directory on all destination AG instances.