Selection-only commands take ids: the objects are selected first (#2130)

object.group, ungroup, the clipping mask and compound path Make/Release,
the Arrange commands, lock, hide, edit.duplicate, object.move, rotate,
scale, reflect, shear and the Pathfinder commands acted only on the
selection, so a script had to send select.set first. Given ids, they now
select those objects (select.set, with its checks) and run as on the
selection, in the same undo step; without ids nothing changes.

crates/engine/src/cmd/edit.rs

@@ -137,7 +137,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Duplicate",
             ["Edit"],
             None,
-            "{dx?, dy?} duplicate the selection in place (offset optional)",
+            "{ids?: [id…] (selected first; default: the selection), dx?, dy?} duplicate the selection in place (offset optional)",
             has_selection,
             duplicate
         ),