Decorators on object literal properties are unsupported in most modern JS tooling, including ts/glint and Prettier 3.0. Using the new native-class-based modifyClass syntax means we can use decorators safely
In #29209, we introduced a callback to the TableHeaderToggle's parent to update the column order. This commit is to update this component to use that callback.
a3d0a9edbb in core converted the Users route to a native class, which meant that `queryParams` merging no longer works.
Extend it manually in `init()`.
