| id | The ID of the item to move. |
| newParentId | The new parent ID. -1 if moved at the root. |
| childIndex | The child index to insert at under the parent. -1 will add as the last child. |
| rebuildTree | Whether we need to rebuild tree data. Set to false when doing multiple operations. |
Moves an item by ID, to a new parent and child index.