Function component that renders the "Customize columns" modal used by both
RoleView and OrganizationsView. UX mirrors PhoenixKit.Users table column
picker: drag-to-reorder selected columns on the left, click-to-add available
columns on the right.
The host LiveView must implement these handle_event/3 callbacks (provided
by PhoenixKitCRM.Web.ColumnManagement):
"hide_column_modal""add_column"(%{"column_id" => id})"remove_column"(%{"column_id" => id})"reorder_selected_columns"(%{"ordered_ids" => [...]})"update_table_columns"(form submit,%{"column_order" => csv})"reset_to_defaults"