Sorted list of children devices (i.e., partitions and unused slots or logical volumes).
Parameters
device: StorageDevice
Returns (StorageDevice|PartitionSlot)[]
Note
This method could be directly provided by the device object. For now, the method is kept
here because the elements considered as children (e.g., partitions + unused slots) is not a
semantic storage concept but a helper for UI components.
Sorted list of children devices (i.e., partitions and unused slots or logical volumes).