Add "Move" to trashed items

[kjac]

When you move a child node to trash and then subsequently moves its parent to trash, the child can no longer be restored, because the original parent is in the trash. And if the parent has been deleted explicitly from the trash, the child can never be restored.

Since we rely on editors being able to move things around in the tree, wouldn't it be reasonable to rewrite the restore functionality to become a simple move operation instead?

I'd be happy to do the work. I've got most of it working already, as you can see.

Update: I realized there's supposed to be a "Move" option to complement "Restore" - but it's not there. This applies to both V7 and V8. I'll prepare a PR.