Mike Fleetwood authored May 19, 2019 and Curtis Gedak committed Jun 11, 2019

Move snap_to_*() method calls from the point when all operations are
added to the list, to earlier when Resize/Move, Paste (into new) and
Create New dialogs are composing the new partition objects.  In
particular for the Resize/Move operation, to just before updating the
file system usage.

This change finally resolves this bug.

Because of the dialog call chains into Dialog_Base_Partition,
snap_to_alignment() must be added into:
* Dialog_Base_Partition::prepare_new_partition() for the Resize/Move and
  Paste (into new) dialogs; and
* Dialog_Partition_New::Get_New_Partition() for the Create New dialog.

Closes #48 - Error when moving locked LUKS-encrypted partition