moveTo method
Moves this item to section and/or index. Forwards directly to
SectionedListController.moveItem:
• section non-null → reparents under that section (at index,
or appended when index is null)
• section null, index non-null → reorders within the current
section
• both null → no-op
No animate parameter: the underlying repositioning ops do not
animate.
Implementation
void moveTo({K? section, int? index}) {
controller.moveItem(key, toSection: section, index: index);
}