VM resize on shared storage should work without ssh

VM resizing should work without ssh connections between compute nodes if they have the same shared storage. Currently VM resizing will always try to do ssh to the new target compute node to check whether the storage is the same or not. As of now this feature requires common ssh keys deployed across all compute nodes which can be a security issue for companies with strict policies and a huge compute node deployment. To avoid this a "is on same storage" flag could be implemented with the vm resize request. A similar functionality is already implemented for vm migrations.