Feature request: Label each disk with the name of the VM that it is attached to, if any

[JoshuaFox]

The current code adds only these labels: the zone of the disk, its name, its region, whether it is attached

Similar to this, need to a method _gcp_instance() to class Disks, and pull that info from the creation-log data which is passed in gcp_object , and they’d get a label like iris_instance

Note: Disk-Instance-Attachment is a mutable value, unlike most values that Iris works with. However, disks are exceptional in that Iris will by default relabel them on each scheduled run in order to capture changes.