Allow for the expansion of physical disks in a storage pool

Allow for the expansion of physical disks in a storage pool just like lvm on Linux. This would be useful in virtual environments and in Azure to be able to expand the physical representation of the virtual disk file. Be it a vmdk or vhdx. This currently allowable on other modern logical volume managers out there. This should be trivial to modify since the meta data is already there. It could be added to the powershell commandlets to rescan-physicaldisk, which would rebuild the metadata on the pool. I have a feedback hub suggestion open on it, which if you could please upvote:

https://aka.ms/AAy4ihw